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

D

David White

n00b
Oct 26, 2018
1
0
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

TURNA

Geezer
Jul 24, 2009
8,432
113
Socialist NY
Where is the hole cut out in the floor It may have come with a 5 speed
 
R

Red78Calais4speed

Apprentice
Feb 16, 2013
90
18
Leominster, Massachusetts
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

DoubleV

Royal Smart Person
Feb 25, 2011
2,070
83
Medina Ohio
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.
 
GP403

GP403

Administrator
Site Admin
Moderator
Feb 25, 2005
3,406
113
Inola, OK
That's a 5-speed car anyway :p

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.
 
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Steveshow

Not-quite-so-new-guy
Apr 13, 2015
44
8
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

TURNA

Geezer
Jul 24, 2009
8,432
113
Socialist NY
OP .....and just like that "poof" he was gone............
 

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