SSG26K

I've got a '72 LT-1 that I've just removed the transmission from. It's a Muncie 4 speed. Can someone help me ID what year transmission it is? R/S tail shaft #3978764, R/s case 7P09, R/S case # 3885010, L/S on shifter housing #3952648, and L/S #7S107786. Any help would be greatly appreciated. I'm thinking this maybe a 1967 transmission.
I know Cast # 3885010 = 65-67
I think #7S107786 is vin# from January 67.
#7P09 may mean built Jan. '67
I don't know what #3978764 or #3952648 mean. Is it an M20, M21, or M22?
Thanks;
Steve

Mike67nv

Take a look at this web site:

http://www.5speeds.com/casting.html

It should answer your questions.

JohnZ

That's a mix-and-match rebuilt Muncie.

The main case is from September '06, originally installed in a '67 Corvette built January 11, 1967.

That tailhousing was used from '71-'74.

The side cover was used from '70-'74.

If it has the original input shaft, 2 grooves is an M20, and one is an M21.

SSG26K

Mike67nv, 78 Silver 78;
Thanks for the link. I was there this morning. That's where I got the casting number as a 65-67. The only real question I had was I didn't understand what they meant by rings to determine if it's an M20-21-22.
JohnZ thanks for identifying the other numbers. One groove on the shaft.
So I guess I've got a mix & match LT-1. That's OK. It's still a very nice car.
Thanks to everyone for their input. Now I've got to buy a new clutch package.

Mike67nv

As John said, identifying by the number of grooves will only work if the input shaft is original - if it has not been replaced and many have been?

Here are a couple of other web sites I've found helpful:

http://www3.sympatico.ca/atkinsom/history.html

http://www.chevcarclubvic.org.au/tec...tification.htm

SSG26K

Thanks Mike. Great information.