need help with manual trans ID
 

I pulled the driveshaft off today and redid the u-joints & rear trans seal on my '72 camino today and while I was under there I pulled some numbers off the trans (two birds one stone :D)

it's a manual 4 speed

it says GM 3925658
then it has an NF but the F is attached to the right leg of the N
that is followed by a small o and a larger 2 ---All this is on the passenger side

sorry if thats a little confusing just trying to describe it as accurately as possible :) thanks in advance

Is it a cast iron case....aluminum case....????

http://hotrodders.com/showthread.php?s=&threadid=23626

Iron case, I'm pretty sure its a muncie as the first 5 numbers match what's on an m-20/m-21 (39256) its just the last two (58) that have me perplexed

Muncie uses an aluminum case. Saginaw has an iron case with all three shift levers in the side cover. ID info for various ratios can be found at www.dandltransmission.com