M21 vs T10

[69L72RS]

Here is a good info site for the ST10

http://fiedlerh.home.att.net/BW.htm

[396L35]

Sorry I couldn't see the pictures on my work computer. It looks like a nice 904 steel case with a 342 1st gear. You can get away with 373's or 410's with a taller tire and still have some low end out of the box. These trannys are extremely strong with the steel case and mid plate and it would be the one I would use instead of the M21. Mark

[x Baldwin Motion]

Thanks everyone for all the help.



I will install the T10 in the Chevelle and save the M21 for the Nova conversion next winter.



Now, about that peg leg 3:08 10 bolt I have. What's the best unit for swapping the guts for a 3:73 posi ?

[budnate]

see if someone is sitting on a old real GM posi, I would check in with Eric 69L72RS he has tons of posi's.

B.

[crash]

You have a 3.42Z ST-10, with or without the 904 steel case this trans is rated at 285 ft/tq...
What makes these weak is the input gear has 17 teeth and the mating gear on the cluster has 31 teeth... M-21 has 26T input/27T cluster...
I buy these all the time with blown input and cluster gear to get the good main case...
Your final drive in first gear with the 4.10's would be 14.022, good for 20ft before you have to shift...
The early Muncie's are 21 1/4" long, the ST-10"s are 22" long, so you might need a drive shaft shortened...
You might want to rethink what your going to do...
E-mail me if you want to talk about it... Crash
[email protected]

[talwell]

I have a BE coded 12 bolt with 5:13's if you are looking

I also have a nice 4 series carrier if you locate a housing.

As for the M21 & T-10. My buddy just did this swap on his 1972 Nova and he did in fact have to shorten the driveshaft.

[x Baldwin Motion]

Yes, the difference between the(my) M21 and the T10 is 1 3/16" (your actual measurements may vary) and requires a driveshaft trimming. Also requires the fatter yoke installed at the front end of the shaft. So, I will now be holding the T10 and waiting for the M21 guts to be put in the new case.

(at least the Nova is finally on the road!)

[x Baldwin Motion]

Picked up M21 with "Italian" guts this afternoon. We'll be putting Olive Oil inside.

[Verne_Frantz]

For Racing I'd recommend ATF. It can take the heat. Olive oil will "cook down" to a sticky slime.