How do I know if a Cutlass came with a factory 4 speed

[David White]

I ran across a 1978 2 door t/top cutlass Supreme, it now has an automatic, but still has the 4 speed linkage. Will the serial # tell me if it came from the factory with a Saginaw. It doesn't run the engine has been changed with what he says is a high output 305. I would want to put it back to a 4 speed , but it needs a lot of work
D. White

 

[TURNA]

Where is the hole cut out in the floor It may have come with a 5 speed

 

[TURNA]

 

[Red78Calais4speed]

The VIN # won't tell you if the car originally had a 4-speed but it may help to narrow it down a bit. The 4-speed in 1978 was only available behind the Chevy 305 V8 2bbl motor. The 5th digit in the VIN would be a U. For a 78 Supreme the VIN would start with 3R47U as the first 5 digits. California and high altitude cars also got the 305 V8 2bbl motor but only as automatics. Those cars would also have a U in the VIN. The 3-speed, 4-speed, and 5-speed manuals weren't available in California or high altitude locations. The presence of a U would help narrow it down a bit. Check the steering column for a key release lever just below the ignition switch. Only manual transmission cars got them. Otherwise, look for the build sheet (most likely under the rear seat). All 4 of the manual trans cars I've owned have been found there.

 

[DoubleV]

Turna, that's an interior pick of my actual car! Pretty funny you probably dug it up on the interwebz somewhere!

Another tell tale sign would be if the radiator was swapped, there's a chance it could had a manual trans radiator.

 

[pontiacgp]

Turna, that's an interior pick of my actual car! Pretty funny you probably dug it up on the interwebz somewhere!

charge him for royalties and/or copyright infringement....😱

 

[GP403]

That's a 5-speed car anyway 😛

If you can dig up the build sheet, it would show MM4 (I think) on there.

Why would they leave the shifter on the floor.... Seems a bit odd. I mean, is the linkage just flapping around under the floor or something? Does it still have the pedals and manual steering column w/ the key release switch? If so, all you'd need can be gotten aftermarket IIRC.

 

[pagrunt]

Besides the MM4 RPO for merchidising there will be the M20 RPO for wide ratio 4 speed, the Saginaw.

 

[Steveshow]

I ran across a 1978 2 door t/top cutlass Supreme, it now has an automatic, but still has the 4 speed linkage. Will the serial # tell me if it came from the factory with a Saginaw. It doesn't run the engine has been changed with what he says is a high output 305. I would want to put it back to a 4 speed , but it needs a lot of work
D. White

I assume that by "but still has the 4 speed linkage", you mean that it still has the clutch pedal and related linkage (?)

 

[TURNA]

OP .....and just like that "poof" he was gone............