1957 Transmission Question

[Erik S. Klein]

I have my eye on a 1957 fuelie nearby that I probably can't afford (or can afford but can't justify in light of my growing family).

From all descriptions the car is in excellent original shape with one major exception: The original 3-speed manual transmission has been replaced by a more modern 4-speed (probably out of a late 50s/early 60s car.)

I'm going to inspect the car on Saturday and if it is as pristine as advertised and if my wife somehow lets us buy it I am sure we'll want it flight judged someday. If we go down that path, I'm pretty sure I'll need a correctly coded 3-speed to replace the installed 4-speed.

After that preamble my questions are:

Did the transmissions carry VIN coding in 1957 or would I be able to effectively bolt on a "correct" date and manufacturing coded transmission for no loss of points?

If I would lose points for an incorrect transmission, would it then just make sense to leave the 4-speed in place?

Thanks,

 

[JohnZ]

There was no VIN derivative stamping on pre-1960 Corvette components, nor is there any definitive way to determine whether a '57 was originally a 3-speed or a 4-speed, except from the VIN number; all manual transmission 57's were 3-speeds prior to about #3500, when the 4-speed installations began around the last week of April. After #3500, it could be either way, and there's no way to prove (or disprove) which one it had originally.

'57 3-speeds were cast-iron Saginaws, and 4-speeds were Borg-Warner T-10's, with an iron main case and aluminum tail housing and side cover; these iron/aluminum 4-speeds (used from '57 through November of 1960) are now VERY rare, and it's not unusual for them to go for $5K. Most of these cars now have later T-10's from late '61 or '62, with aluminum main cases, which are much more plentiful.

Transmission and axle numbers are not judged by the NCRS in Flight Judging (except for "Bowtie" judging); they are only judged by appearance, based on what can be seen with the car on the ground. It's not uncommon for pre-1960 cars to have the aluminum main case (on a later replacement transmission) painted to "appear" like cast iron.

Essentially, if the car is prior to #3500, it needs to be a 3-speed for full credit; after #3500, it can be either. In any event, the manual transmission on a '57 is only allocated 17 originality points, so there isn't much to lose whether it's "correct" or not. Do whichever one you like best, and don't worry about the points; the 4-speed is much more satisfying to drive, and that's what the car is all about.