I got all of my rebuild SM420 parts from these guys.

http://www.americanpowertrainwarehouse.com/sm420-48-67-manual/

I watched the GM slideshow numerous times. I have a friend with a press so that helped. I'm no transmission guy but I didn't have any issues.


Don't pay no mind to that whirrin' sound, she uses a little oil but outsida' that she's cherry.