Need help with tranny id (please)

[Chevy409]

I just bought 3 standard trannies, all 4 speeds, and need a good site for decoding these suckers. They're all cast iron and look very similar but each has different numbers. Anyone point me in the right direction? Oh, and they all came from Chevys, two from 4-wheel drives and one came from a 2 wheel drive. Thanks /forums/images/graemlins/ears.gif

 

[Chevy409]

ttt /forums/images/graemlins/confused.gif

 

[4x4Freak]

Chevy used two different 4spds that I know of. They used the SM420 in the 50s-70s(???) and then switched to the SM465 after that.

The location of Reverse is the easiest way to tell the difference between the two. The 420 has reverse down and to the left while the 465 is down and to the right. I believe one of them also has an inspection plate on both sides; I think it is the 465, but I'm not too sure. Hope this helps.