|
Re: Stock rear gear ratio info
1/2 ton
12 bolt: 3.07, 3.73, 4.11, 4.56
3/4 ton
corp/eaton 10 bolt: 4.10, 4.57, 5:13, 6:13
Dana 60: 3.54
the 3.54 was standard for the big block 400 as it didn't need as much gearing. the 3.07 was pretty standard on the 1/2 ton with an auto unless you ordered otherwise. my 72 burb c20 automatically came with a 4.57 because it is 2wd and has a manual 3 on the tree. the 4x4 burb got the 4.10 normally as did most c/k 3/4 ton pickups as they are lighter. i put a 4.10 third member in my burb because it was an easy swap and the 4.57 is a little too low once you get rolling. with a q-jet in place of the 2bbl the 307 is much spunkier now because of the quick response small primaries and the extra air flow potential. i picked up a 66-69 saginaw-borg warner overdrive trans (my rig is a 3 on the tree) and that will give me a far better highway ratio than a straight 3.07.....so i get the best of both worlds.
|