Have a 1980 ford f 150 4X4 with a 351 w. The motors all done over and pretty built, have everything thats in the motor listed in my gallery. The truck has a c6 with 31s for tires. Thats the biggest it will ever see i may even go back to the 235/75 r 15. Anyways im wondering with whats in the motor if i should go to a lower gear like 4:11. Also the truck has a c6 trans. I never tow with it it would be simply for performance gains. Right now the truck has 3:50 gears. Also does anyone know what it might tach at 65mph with 4 :11 gears? Dont really care about the gas milage its already horrible lol

 

Assuming everthing stays the same and you just change rear-end ratios, the 4.11s will be about 15% shorter than the 3.50s. So you'll turn about 15% more RPM at any given speed.

 

or maybe go lower then 4:11 just trying to figure what would work best with the other mods ive done. the rpm range on the cam in the motors 2000 rpm to 6500 if that helps also was calling around getting prices on gears today, are precision gears a decent brand? Also ive seen some dana 44 listed as a reverse rotation gear, they didnt mention that when i called on the gears but wanted to make sure that it doesnt have that. any help is greatly appreciated