Jolly has a lot of good info on his transmiision site. However, the SM465 (later called the CH465) was the successor to the SM420. I didn't know GM light trucks were available with the New Process transmissions. My 71 GMC, 72 Chevy, 76 Chevy, 80 Chevy, and 86 Chevy (OK, so I like GM) all had the 465 4 speed as standard equipment. It had the same ratios as the 420 except for 1st gear, which was 6.55 instead of the 7.06 of the 420. I still think the 420 had a crisper shift, although I can't explain why. My 96 has a 4 speed, too, although its one of those....what do you call them....'automatics'. Its...uhh...a Chevy.
