Tuesday, March 27, 2012

Common Parts between the Nova and Omega

Here is some really good information I have been putting together and accumulating with hours of internet research.  Its really hard to track down all the parts that fit between different years of Novas, and it is even harder to track down what parts are common to all X-body cars (Nova and Omega for example).

This is some of the information that I have been able to piece together that may be useful to others.


Chevrolet Nova vs. other X-bodies (Omega, Ventura/Phoenix, and Apollo/Skylark)

Nova's share a fair amount of common body panels with their X-body cousins of similar years.
Similar models/years include:
  • Oldsmobile:
    • 1973 - 1974 Omega <-----> 1973 - 1974 Nova
    • 1975 - 1979 Omega   <----->  1975 - 1979 Nova
  • Pontiac:
    • 1971 - 1972 Ventura   <----->  1968 - 1972 Nova
    • 1973 - 1974 Ventura   <----->  1973 - 1974 Nova
      Note: '74 GTO was based on the Ventura platform
    • 1975 - 1977 Ventura   <----->  1975 - 1979 Nova
    • 1978 - 1979 Phoenix   <----->  1975 - 1979 Nova
  • Buick:
    • 1973 - 1974 Apollo   <----->  1973 - 1974 Nova
    • 1975 Apollo   <----->  1975 - 1979 Nova
      Note: '75 Apollo was available only as a 4 door
    • 1975 - 1979 Skylark  <----->  1975 - 1979 Nova
Common parts include:
  • Radiator Support ('75 - '78 is the same for all X-bodies, '79 is likely the same too -- not verified)
  • Battery Tray (probably the same but not verified)
  • Front Subframe, Suspension, and Steering Components (might be some differences with some pre-75 steering linkage)
  • Front Fenders (1975 and later X-body fenders appear to be the same with marker light and emblem hole exceptions)
  • Front Inner Fenders (probably the same but not verified)
  • Side Marker Lights (not the same on all X-bodies)
  • Hood Hinges
  • Windshield Molding
  • Rocker Panels
  • Doors
  • Exterior Door Handles
  • Most Interior Parts (see ** note below)
  • Vent Panels (see *** note below)
  • Floor Pans
  • Quarter Panels (slight differences where the tail lights wrap around on some models)
  • Gas Tank
  • Trunk Floor
  • Trunk Lid
  • Hatch Lid (not verified)
  • Rear Window Molding
  • Rear Bumper (may be cosmetic differences for '74 and earlier)
The different parts include:
  • Front Bumper
  • Bumper to Grille Filler Panel
  • Grille and Grille Brackets
  • Headlight Bezels
  • Parking/Turn Signal Lenses (in grille or bumper)
  • Front Fender Extensions/Header Panel
  • Hood Latch
  • Hood
  • Cowl Panel
  • Tail Light Panel
  • Tail Light Lenses
** Interior parts are generally physically interchangeable between Novas and same/similar year X-bodies. However, there are some upholstery pattern and emblem differences on some parts. The 78/79 Pontiac Phoenix dash and instrument panel is an exception. They used a unique instrument panel and what appears to be a 75/76 Nova style dash pad. The 77-79 Buick Skylarks and Olds Omegas appear to use the same basic style instrument panels and dash pads as 77-79 Novas.
*** These vent panels are located on the B-pillars of 75-79 2-doors and Hatchbacks and serve as functional air outlets. Most have vertical ribbed louvers although some (mostly Pontiac I think) have horizontal louvers. 75-79 4-doors have decorative vent panels on the C-pillars (the functional ones are in the rear door jambs).


General Body Style Differences (2 door / 4 door / hardtop / sedan / station wagon / convertible)



Both 2 and 4 door cars are the same from the firewall forward. Floor pans, trunk floors, and trunk lids are also interchangeable between 2 and 4 door cars. Dashboards, instrument panels, and steering columns are also the same. Front seats will also interchange, but 4 door seats do not fold ahead for access to the back seat.
All '68 - '79 2 and 4 door glass is entirely different between the two body styles. Most '62 - '67 glass is different as well, but windshields are common for 2 and 4 door sedans as well as wagons.
A hatchback was available from '73 - '79. These share many parts with 2 doors of the same year range ('73 - '74 and '75 - '79). The differences are in the rear window, rear seat, and rear interior pieces.
From '62 - '67, both coupe and sedan models were available. Sedans have a stationary frame around the side window openings. They are often called "post cars" due to the post that remains between the front/rear windows when they are both rolled down. Many parts will interchange between sedans and hardtops. The exceptions include the glass, associated trim, doors, and roof.
The '62 - '67 Chevy II/Nova was also available in a station wagon. Everything from the firewall forward is the same as all other body styles of the same year. Front doors are interchangeable with 4-door sedans. Rear doors are also interchangeable with 4-door sedans but require the wagon window frame to be transferred over to the replacement door. All other roof, rear window, and tailgate parts are pretty much unique to the station wagon body style.
Convertibles were available in '62 and '63. Many parts (such as the doors) are interchangeable with '62 - '65 2 door hardtops.




Interior Parts

  • 1968
    In general, many '68 interior parts are unique to that year. This was the first year for the new body style but the last year for the dash mounted ignition switch. That made for a unique steering column, dash, and instrument panel. Interior door lock knobs were moved further forward in '69 so the '68 doors and interior door panels are unique. Seats were also unique to '68 since head restraints were optional that year. The ash tray and brake/clutch pedals are also unique to '68.
  • 1969 - 1972
    Nearly all '69 - '72 interior parts are physically interchangeable. However door panel and seat upholstery patterns/styles were changed from year to year. High back bucket seats were introduced in '72.
    Instrument panel outer bezels are all interchangeable from '69 - '72. The '72 bezel is slightly different since it has a "Seat Belt" light. Later year ('73 - '76) bezels will fit a '69 - '72 but they have a different pattern ("grained" instead of "ribbed") and they do not use a cover panel under the steering column. Use of a corresponding year under-dash steering column bracket may be necessary to properly align the height of the column with a '73 - '76 bezel.
    1969 - 1970 instrument panels have greenish colored numbers while the otherwise similar looking '71 - '74 instrument panels have white numbers. Cars equipped with the optional RPO-U17 special instrumentation package feature a tachometer in the left hand opening normally occupied by the gas gauge. The gas gauge on these cars is moved to a gauge pod at the front of the console (which also includes an oil gauge, temperature gauge, and ammeter).
    1969 - 1970 heater and AC control panels also have greenish colored lettering while the otherwise similar looking '71 - '72 control panels have white lettering. The '73 - '76 panels are also very similar (and interchangeable) but they have the defroster control labeled "DEF" instead of "DE-ICE".
    Steering columns are interchangeable from '69 - '74. A tilt column option became available in '73. The '73 - '74 tilt column is a direct bolt-in swap into a '69 - '72. A later '75 - '79 Nova column can also be used with some minor modifications. See the "Miscellaneous" section below for details.
  • 1973 - 1974
    Most '73 - '74 interior parts are interchangeable between the two years. The seat belts, headliner, and headliner trim are different due to the retractable shoulder belts introduced in '74. 1974 Novas were equipped with a seatbelt-starter interlock system that used weight sensors in the front seat(s). This interlock system can be easily disabled so swapping in different seats without the sensors is not a problem.
    '73 and '74 instrument panel outer bezels are identical. Many '75 and '76 Novas also use a very similar looking (but slightly different) outer bezel with a different style instrument cluster mounted in it. Some models (such as the '75 LN and '76 Concours) used special color-coordinated and/or woodgrain instrument panel bezels. These would still physically interchange with a '73 - '74 bezel though. The earlier year ('69 - '72) bezels will also fit a '73 - '76 but they have a different pattern ("ribbed" instead of "grained") and they use a cover panel under the steering column. Use of a corresponding year under-dash steering column bracket may also be necessary to properly align the height of the column with a '69 - '72 bezel.
    '73 and '74 use the same instrument panel as '71 - '72. A '69 - '70 instrument panel will interchange but it has greenish colored numbers instead of white. Cars equipped with the optional RPO-U17 special instrumentation package feature a tachometer in the left hand opening normally occupied by the gas gauge. The gas gauge on these cars is moved to a gauge pod at the front of the console (which also includes an oil gauge, temperature gauge, and ammeter). The optional console used in '73 - '74 Novas is similar to the '68 - '72 console except for the area around the shifter which bumps out towards the driver seat.
    Heater control panels are identical from '73 to '76. Earlier '69 - '70 (greenish lettering) and '71 - '72 (white lettering) panels will also interchange but the defroster is labeled "DE-ICE" instead of "DEF".
    The '73 - '74 dash pad is nearly the same the '69 - '72 pad but the grain texture is slightly different.
    Steering columns are interchangeable from '69 - '74. A tilt column became an option starting in '73. A later '75 - '79 Nova column can be swapped into a '74 or earlier Nova with minor modifications. See the "Miscellaneous" section below for details.
    The hatchback body style was introduced in '73. It shares many interior parts with 2-door cars but the rear seat and rear interior panels are unique to the hatchback body style.
  • 1975 - 1979
    For the most part, '75 - '79 interior parts are interchangeable. The dash (re-designed for 1977) is the most significant exception.
    The "regular" '75 - '76 Nova instrument panel outer bezel is very similar looking to the '73 - '74 outer bezel but the "grained" areas below the speedometer and around the radio and light switches are slightly different size. The bezels are physically interchangeable from '73 through to '76 though. 1975 LN and '76 Concours Novas used special color-coordinated and/or woodgrain bezels that are otherwise physically interchangeable with the "regular" bezels.
    The instrument panel (speedometer and gas gauge assembly) is unique to '75 - '76 but it is physically interchangeable with the '69 - '74 instrument panels. As with the earlier years, the RPO-U17 special instrumentation package locates a tachometer in place of the gas gauge for '75 - '76 and re-locates the gas gauge to a gauge pod on the console. The '75 console gauge pod is identical to the earlier years. The '76 gauge pod is very similar but uses a voltmeter instead of an ammeter. The '75 - '76 console is different than the earlier years.
    The '75 - '76 dash pad is unique to those years but appears to be physically interchangeable with a '69 - '74 pad. This is due to the fact that the metal dash under-structure remained unchanged as did the shape of the instrument panel bezel where it meets up with the dash pad.
    Heater control panels are identical from '73 to '76. Earlier '69 - '70 (greenish lettering) and '71 - '72 (white lettering) panels will also interchange with '75/'76 but the defroster is labeled "DE-ICE" instead of "DEF". The '77 - '79 control panels are different and will not interchange with the earlier year panels.
    Both the dash pad and instrument panel were changed in 1977. Because of this, the '77 - '79 dash pads, instrument panels, and instrument panel bezels are not interchangeable with earlier years. The metal dash under-structure remained unchanged so it may be possible to swap all of the parts as a group. The electrical connector on the back of the instrument panel was also changed so a wiring harness swap would also be required. The new '77 - '79 instrument panel design has 4 round gauge openings. This allowed all optional gauge packages to be located in the instrument panel. A console gauge pod was no longer necessary.
    Steering columns are the same from '75 to '79. Steering wheels were changed in '78 (style only -- they're still physically interchangeable). Seat belts were also changed in '78 (single roof mounted retractor).
    The hatchback body style was still available from '75 - '79. Again, they shared many interior parts with 2-door cars except for the rear seat and rear interior panels. An optional Cabriolet vinyl roof was available on '75 - '79 2-door Novas which used unique interior panels around the rear side windows.
  • Miscellaneous Interior Parts
    • A '75 - '79 Nova/X-body steering column (including tilt columns) can be swapped into a '69 - '74 with some minor modifications. The '69 - '74 steering columns have a flange attached directly to the lower end of the steering shaft. A flexible "rag joint" coupler joins the steering box to that flange. The '75 - '79 steering column has a splined lower end which connects to an intermediate shaft via a U-joint coupler. The lower end of the intermediate shaft has the flange that attaches to the "rag joint" coupler on the steering box. A '75 - '79 column can be installed in a '69 - '74 using the following guidelines:
      • Remove the intermediate shaft from the lower end of the '75 - '79 column.
      • Remove the flange from the lower end of the intermediate shaft and install it directly onto the splined lower end of the steering column.
      • Note that the end of the intermediate shaft is purposely deformed to hold the flange in place. Attempting to remove the flange over the end of the shaft will likely distort and ruin the splines inside the flange.
      • The flange can be removed without damage by sawing the intermediate shaft off just above the flange and pulling the flange off over the cut end of the shaft.
      • When the flange is re-installed on the lower end of the column, it would probably be a good idea to secure it with a set screw or some tack welds if it is not a tight press fit.
    • A windshield wiper delay control was available as an option (RPO-CD4) starting in 1975. Due to the similar instrument panel bezels, the '75 - '76 wiper delay system can be easily retrofitted into a '72 - '74 Nova. The wiper switch plug is slightly different on '69 - '71 Novas so additional modifications would be necessary.
      This system consists of a special wiper switch and a control module that mounts under the dash. It simply plugs into the existing wiring and uses the existing wiper motor. A similar system was used on '77 - '79 Novas but uses a different switch due to the dash re-design and therefore is not suitable for retrofit into earlier years.
    • The rear door pull straps and chrome end caps on '75 - '79 4-door cars are interchangeable with the ones on '73 - '74 2-doors.
    • The interior door release handles used in '75 - '79 Novas appear to be the same as the ones used in the 80's and early 90's Chevy Celebrity and similar cars such as the Pontiac 6000, Olds Cutlass Ciera, and Buick Century.




Mechanical Parts

  • Engines
    • Engines in early ('62 - '67) Chevy II/Novas used special front sump oil pans to clear the steering linkage. Small block V8 engines (283s and 327s) used in these cars also had recessed oil filters and a special location for the bellcrank pivot on manual transmission cars. The front sump oil pans, pivot relocation adapters, and other '62 - '67 V8 conversion parts are available through most restoration parts suppliers
    • Most 60's small blocks use heads without accessory holes. These engines also use short water pumps and often mount the alternator on the driver side. Power steering pumps (if equipped) are mounted below the alternator and air conditioning compressors (if equipped) are mounted on the passenger side of the engine. Since there are no accessory holes in the heads, the lower alternator mount is usually bolted to (or cast into) the exhaust manifold. The upper alternator mount attaches to either a stud in place of the top left water pump bolt or to a mounting point on the front of the intake manifold. The power steering pump mount attaches to the front of the block (where 50's front engine mounts used to go) and wraps around to one of the side engine mount bolts. The lower A/C compressor mount attaches to studs that take the place of a couple exhaust manifold bolts. The upper A/C compressor mount attaches to a bracket bolted to the intake (w/longer bolts).
    • Most 70's small blocks use heads with accessory holes. This results in an entirely different accessory mounting scheme than on the 60's engines. Now alternators are on the passenger side and air conditioning compressors (if equipped) are on the driver side. Power steering pumps (if equipped) stayed on the driver side but received new mounts. These engines also use long water pumps. For the most part, 70's and 80's small block (and some V6) accessory mounts are interchangeable. However, there were slight changes that took place over the years so it's best to get a complete set of compatible mounts from a donor engine when performing an engine swap.
    • '79 and earlier small blocks had the oil dip stick on the LH (driver) side. It was moved to the passenger side in '80.
    • Timing tabs and harmonic balancers were also changed sometime around '76 or '77. The earlier timing tabs are on the upper LH side. The later ones are on the top (12:00 position).
    • Starting in '75, inline 6 engines began using an integral head and intake assembly. These can be swapped for a '74 or earlier head for use with aftermarket intakes.
  • Engine Compartment Items
    • All 1962-70 Chevy II/Novas use a windshield washer fluid tank that fits into a metal mounting bracket. 71-74 Novas use a similar looking tank that attaches to the inner edge of the driver side fender with two screws. 75-79 Novas also have the washer tank secured to the inner edge of the driver side fender but these years use a different tank that incorporates an electric washer pump.
    • All 1968-79 Novas use the same style rectangular body windshield wiper motor. 68-74 have a mechanical washer pump mounted to the wiper motor. 75-79 have an electric washer pump mounted at the bottom of the washer fluid tank.
    • Most Novas with 6-cyl engines did not originally use a fan shroud. Instead, they simply have a rounded guard built into the top radiator mounting plate. Fan shrouds were used on all Novas with V8 engines as well as later 70's Novas with 6-cyl engines and air conditioning.
    • Coolant recovery tanks were added sometime around 1973 and three different designs were used over the years. The 73/74 style tank mounts to the inner edge of the front fender up on top of the inner wheel well. I believe these tanks were usually located on the passenger side fender except on cars with A/C (which had the tank on the driver side). The second design tank was used only for 1975. It looks and mounts similar to the 73/74 tank. The 75 tanks were mounted on the passenger side fender with L6 engines and on the driver side fender with V8 engines. The third design tank was used from 1976 to 1979. It mounts inside the passenger side fender (next to the battery).
    • Air intake snorkle ducts were first used in 1975. All 75-79 6-cyl engines had a plastic duct/tube connecting the air cleaner snorkel to the oval shaped hole in the inner edge of the driver side fender. 1975 V8's had a similar setup with a flexible duct hose connecting to the oval shaped hole in the inner edge of the passenger side fender. 1976-79 V8's had a plastic duct/tube with it's open end fastened to the top radiator support plate.
  • Transmissions
    • Both 3 and 4 speed manual transmissions were available in Novas. Two speed (PowerGlide) and 3 speed (TurboHydramatic) automatic transmissions were also available. This makes manual to automatic or automatic to manual transmission swaps fairly straightforward. The easiest way is to locate a donor car with the appropriate type of transmission. 
    • All Chevy engines (inline 6, small and big block V8) use the same bellhousing bolt pattern which helps simplify engine/transmission swaps. However, not all transmissions are suitable for use behind all engines. For example, the TH200 transmissions used in some '76 and '77 Novas didn't even hold up well behind the 305s that GM used them with.
  • Front Subframe / Suspension / Steering
    • 1962 - 1965 share a common front subframe and suspension design. Due to improvements/changes, many '62 front end parts are somewhat unique to that year.
    • 1966 - 1967 have a subframe and suspension design that is similar to '62 - '65. The major difference between the '62 - '65 and '66 - '67 subframes is the inner fender attachment points (bolts are horizontal for '62 - '65 and vertical for '66 - '67). 1967 was also the first year for a dual chamber master cylinder and collapsible steering column. These changes made for different brake lines and a different steering box.
    • 1968 - 1974 Novas share a common front subframe and suspension design. The 1974 subframes have different front bumper mounting holes than the 1968 - 1973 subframes. The steering linkage is located behind the spindles so this design is often called "rear steer".
    • 1975 - 1979 Novas share common front subframes and front suspensions. The steering linkage is located in front of the spindles so this design is often called "front steer". 1979 Novas used spindles/rotors with larger outer wheel bearings.
    • The power steering boxes used from '68 - '79 are Saginaw 800 series boxes. They are interchangeable from 1968 - 1974. I believe that a 1975 - 1979 box will also work as long as a '68 - '74 pitman arm is used to account for the front/rear steer differences. 1968 - 1974 boxes have 4 mounting points but one is unused. The unused mount was eliminated on later boxes (starting sometime around '75). Later, metric fittings were used which will require either the matching lines and pump or custom made lines.
    • Manual steering boxes are also interchangeable in the 1968 - 1974 and 1975 - 1979 year ranges. A swap across those two year ranges is possible if the correct pitman arm is used to account for front/rear steer differences.
    • Front subframe mounting bushings are the same for 1968 - '74 Novas (and other X-bodies) and 1967 - '69 Camaros/Firebirds.
    • See below for more interchangeable Camaro/Firebird front subframe and suspension parts.
  • Rear Axles
    • 1962 and 1963 ChevyII/Novas used rear axle assemblies with removable center sections (like 55-64 Chevy full size car axle assemblies). These years used 4-lug wheels.
    • 1964 - 1967 ChevyII/Novas used either 8.2" 10-bolt or 8.875" 12-bolt rear axle assemblies depending on the car's original engine. The vast majority of 64-67 ChevyII/Novas were equipped with the 10-bolt. Only a few cars (those equipped with high performance 327's) received the 12-bolt rearends. Most (if not all) 64-67's have 5-lug wheels. The overall width and spring perch location is the same so a complete 64-67 rear axle assembly can be swapped into a 62-63 in order to upgrade from 4 to 5 lug.
    • 1968 - 1971 Novas were also equipped with either 8.2" 10-bolt or 8.875" 12-bolt rear axle assemblies. Again, the 10-bolts are most common with the 12-bolts being used in cars equipped with big block V8's and high performance small block V8's. Due to the new body/chassis style, the '68 and newer rear axle assemblies are wider than the ones used in 62-67 ChevyII/Novas.
    • 1972 - 1975 Novas were all equipped with 8.5" 10-bolt rear axle assemblies. These were used with all engine sizes and are nearly as strong as the earlier 12-bolts. The overall width and spring perch locations remained unchanged so these axle assemblies are a bolt-in swap into '68 - '71's.
    • 1976 - 1979 Novas were equipped with either 8.5" 10-bolt or 7.5" 10-bolt axle assemblies. All 76-79 V8 Novas (except the '76 305) used the 8.5". The 76 305 and virtually all 76-79 6-cyl Novas used the weaker 7.5" rear. Again, the overall width and spring perch location remained unchanged so '76 - '79 axle assemblies are a bolt-in swap into '68 - '75's and vice versa. There is a driveshaft length issue when switching from a 7.5" 10-bolt to any of the other three (8.2", 8.875", or 8.5") axle assemblies though. The driveshafts used with the 7.5" rears are about 1" longer.
    • I think axle shafts may be interchangeable between the '68 - '71 8.2" 10-bolts and the '72 - '79 8.5" 10-bolts. Other than that, there are no major internal parts that will interchange among the different sizes and types of axle assemblies.
    • See below for interchangeable Camaro/Firebird rear axles.
  • Brakes
    • Front disc brakes became an option in 1967. 
    • Front discs remained optional on 1968 - 1974 Novas (they were standard equipment on the Nova SS from '69 - '72 though). All 1968 - 1974 disc brake assemblies are physically interchangeable but '68 discs used special 4-piston calipers and two piece rotors that are difficult/expensive to find repair/replacement parts for. So '68 style disc brakes are not really the best choice for most conversions.
    • 1967 - 1969 Camaro/Firebird disc brakes will also fit 1968 - 1974 Novas but again, the '67 and '68 discs used the more expensive 4-piston calipers and 2-piece rotors. Other pre '75 X-bodies ('71 - '74 Ventura, '73/4 Omega, and '73/4 Apollo) are also suitable disc brake donor cars for '68 - '74 Novas.
    • 1967 - 1970 disc brakes used a separate distribution block/switch and metering valve. The distribution block/switch is the same as what is used with 1967 - 1974 drum brakes. 1971 - 1979 disc brakes used a combination valve that included a metering valve, proportioning valve, and differential pressure switch all in one housing.
    • Front disc brakes became standard equipment on all Novas in 1975. The front suspension/subframe was also re-designed in 1975 so '75 - '79 disc brakes will not fit earlier Novas. Power brakes were still optional on '75 - '79 Novas but they were a required option when a V8 engine was ordered. 1975 - '79 power brake boosters are interchangeable. The push rod can be modified in order to use a '75 - '79 booster on a '68 - '74 Nova.




3 comments:

Jen said...

Well, you've definitely been doing your homework!

Lynne said...

This will be so helpful to anyone else that might be considering a similar conversion.

Madrios Chang said...

I have a 1973 Oldsmobile hatchback that has a badly wrecked left side rear end! Does anyone know what other body styles I can use for this fix?