MotorHead

I am trying to figure out which transmission I have more to the point what first gear ratio I have. Someone posted a very simple formula for what would work well at the track and said that if you multiplied your first grear by the rear end and it came out to between 8 and 10 ( not sure of the exact numbers here) than that would work good on the drag strip.

For example of your first gear was 2.64 and your rear end was 3.55 then you would be at 9.37 and within the range. Anyway I took the numbers off my tranny and they are:

6.13.79-1
MLT 1198 A
1304 065 903
FpC4

Here are the Borg Warner tranny gear ratios:

TRANSMISSION 1ST 2ND 3RD 4TH 5TH

Borg-Warner T-5 1983-1987 (V8) 2.95 1.94 1.34 1.00 0.74
Borg-Warner T-5 1988-1992 (V8) 2.95 1.94 1.34 1.00 0.73
Borg-Warner T-5 1988-1992 3.35 1.99 1.33 1.00 0.68
Borg-Warner T-5 1988-1992 3.97 2.34 1.46 1.00 0.79
Borg-Warner T-10 A-code 2.54 1.92 1.51 1.00 n/a
Borg-Warner T-10 C, F-code 2.20 1.64 1.31 1.00 n/a
Borg-Warner T-10 D, E, G-code 2354 1.89 1.51 1.00 n/a
Borg-Warner Super T-10 P-code 2.43 1.76 1.47 1.00 n/a
Borg-Warner Super T-10 S-code 2.43 1.61 1.23 1.00 n'a
Borg-Warner Super T-10 U-code 3.44 2.28 1.46 1.00 n/a
Borg-Warner Super T-10 V-code 2.23 1.77 1.35 1.00 n/a
Borg-Warner Super T-10 W-code 2.64 1.75 1.34 1.00 n/a
Borg-Warner Super T-10 X-code 2.64 1.61 1.23 1.00 n/a
Borg-Warner Super T-10 Y-code 2.88 1.74 1.33 1.00 n/a
Borg-Warner Super T-10 Z-code 3.42 2.28 1.46 1.00 n/a
Borg-Warner Super T-10 AA-code 3.29 1.72 1.00 1.00 n/a
Borg-Warner Super T10 BB-code 4.17 2.28 1.46 1.00 n/a
Borg-Warner Super T-10 CC-code 2.88 1.91 1.33 1.00 n/a

If anyone can figure this out I would appricate it because of the fact that most people would say that 3.08 rear end is not too good to racing with but if you had say, a 2.88 first gear then you come out with a 8.87 ratio and that falls in the range that is supposed to be OK for the strip. :D

45ACP

According to my notes the only 4-speed available from 80-81 was a Borg-Warner Super T10 with ratios: 2.88, 1.91, 1.33, 1.00, (R)2.78. The RPO was "M18".

MotorHead

Thanks fior the help. I forgot to mention that I believe mine is a transplant as I have the removable crossmember. I think that the date is stamped on the tranny though and it looks like 6/13/79 so it still might be an 80 tranny.

45ACP

Woops, didn't even notice the dates.

I'm not certain how much "lag" there was between the completion of a tranny and installation, but June of '79 into a car that would be built for model year '80 seems like a loooong time to me. I suspect you have a very late '79 unit.

"1304 065 903" is a Borg-Warner # that I have seen before, so I'd say you have a Super T-10. If the tranny was originally out of a '79 Vette -and has not had the gear set altered from stock- it will be one of the following . . .

M20 - wide ratio - 2.64, 1.75, 1.34, 1.00, (R)2.55
M21 - close ratio - 2.43, 1.61, 1.23, 1.00, (R)2.35

If the donor car was something other than a Vette or the gear set was changed by a past owner . . . your guess is as good as mine as to what you have there.