If it's got the short gears that these rigs always had-potentially 7.10:1-then a small block will be better, because it is more a high RPM engine. If it's got the usual T-150 two speed with high of 6.40:1 then actually a 327 or 350 will be fine. Also, these trucks came stock with a 283 option, so the stuff to fit it in the frame will be somewhat easy to find, at least in this forum.
I wish it were still possible to find the taller 5.83:1 gears GM offered for that differential, because then that would mean lower RPM at modern (more than 54mph) cruising speeds.
If I had a million dollars, I'd pay Georgia Gear to produce a run of taller gears for our old two tons.
Last edited by Tronman; 01/02/2026 9:55 AM.
