I started a thread a few months ago asking for advice on if I should go with 4.10 or 4.56 gears.
http://67-72chevytrucks.com/vboard/s...d.php?t=369789
After a lot of research and explanations from folks a lot smarter on this stuff than me, here's some logic -
Average truck tires are 28" give or take. Don't forget - my truck was originally a 2 wheel drive!
With 33" tires and 4.10:1 differential.
33/28=1.18
4.10 x 1.18 = 4.84:1
28" tires with a 4.10:1 differential = 33" tires with a 4.84:1 differential or
33" tires with a 4.10:1 differential will have the effective ratio of a 3.48:1 differential compared to 28" tires.
Since the cam I already bought calls for low gears (3.73 or numerically higher), and the fact I've already got some decent size tires and I may go with larger tires and a manual tranny, I decided to go with a 4.56 ratio. Front Dana 44 and rear 12 bolt Richmond Gear ring & pinions are enroute from Summit racing now. Merry XMas to me.