700r4 or what?

[coonster]

ok it has been a long time. So i have the 67 and i am converting from k10 to k20. the rear end i am take out is cool 4-10 and a posi!!!! the front is 4-11. so the k20 has 3.72 front and back. Yes i am trying to get better gas. so right now at 55 mph with 4 speed tran and 3.72 i am at 3300rpm. so i think i like to put a 700r4 in it ( i have a 99 sub which got hit ) i wa going to use that. One other que to u guys how have 700r4 what are u guys grtting in mpg? In the suburban highway i got 22 and towing i got 19. I should get about 15 hope.