Thread: 1974 Avanti T-10 information

I've been all over the site, Bob Johnstones site and the internet at large looking to understand exactly what T-10 I have in the 74 Avanti.

The numbers make me think it's the OEM 4-speed but I'd like to check with the experts to be sure and also see what the ratios are.

Case # 13-04-065-902 which makes it a cast iron case, I believe. The tail shaft is also cast and has T-10K-7 cast in it.

Build date is (B or 8)-10-73 which makes it a 73 build in either Feb (my guess) or August.

Metal tag on the side plate under one of the top bolts --
1700391
A815T10P

The input shaft is 10 spline with a single groove.

Output is 27 spline.

As I've said, I'd like to know the gear ratios in particular.

As always, thanks for any additional information.

Bob

The T-10 in question is now setting in the polebarn, all cleaned up and ready for painting. I opened it up and it appears to have been rebuilt as the syncro etc. look great.

I'm answering my own question to help if someone else searches the forum for similiar data.

First gear is 2.43 and that should make the ratios 2.43/1.61/1.23/1.00 with a single ring on the input.

The serial # is WJ1032 that should make it a first series ST-10 manufactured October (J) 10th 1973 on the second shift. So if this is the second to last Avanti II four-speed, it has one of the last first series ST-10's made also. It still has the 10 spline input, 27 spline output and 7/8" shaft.

FYI

Bob