Check out 6066 gmc (google search), Jolly Goodfellow's site, has LOts of info on GMC V6. That little carb on those early engines is a real choker. Might want to see if a 305E mainifold will fit it, I put a 210 1/2 quadrajet (off a 301 Pontiac) on my 64, it purrs like a kitten. The manifold (305e) is a choker for it also, but that pontiac engine was not a big breather either. Check out their HEI conversion. Mine runs as good as a late model, no raw fuel smell, missing, ect with the modern carb (elec choke) and HEI. Well worth the trouble. You will pick up 15 hp with better breathing, might need bigger pipes, Mine is just "regular old exhaust" might put duals on one day.
