[capev86]

yeah....i forgot that you could get a big block in the 1/2 ton trucks.....like a bare bones precursor to a chevy SS of the early 90's. even with the 400bb, a 3.07 is still kinda soft if you do any serious towing because it only has 30 more ft-lbs than the 350 according to my 72 burb brochure. however it would be perfect for a modern diesel swap (you'd still want a mild overdrive gear with a diesel). perhaps you could special order a 3.73 or a 4.11 if you needed it for towing. there was also a 4.56 available on 3/4 ton trucks and that was for the the dana 60 without the big block as the 4.57 is the corp/eaton. 3.73 was standard on all 1/2 ton burbs and the 4.10 was an option available for the K20 burbs.

i like a 3.42 to 3.73 on a 1/2 ton and a 3.73 to 4.11 range on a 3/4 ton (unless i had huge diameter tires). an overdrive is the other piece of the puzzle and there are several bolt-in routes you can go with depending on what model/type of trans you have to begin with!