Rear Ends

[kfreeman1966]

Hello all, I have a 66 with a 350,mild cam...automatic. it has a 71 model rear end in it and a turbo 350 auto trans. Here is the question. If I put a 700 R4 Auto trans in it, what would be the best gear ratio to go with. (lets keep in mind the truck is a daily driver and is my 18 y/o daughters). looking for great driving and good gas mileage.

Thanks,
Keith

[Alan's Classic]

Hey Keith, there are several gear ratio calculators out there where you put in the specifics of RPM, speed, tire size and final drive.

Here's the first one that popped up on a google search. http://www.richmondgear.com/101032.html

[Greshampiglet]

I Have a Crate motor 350 and a 700R4 anda 3.54 rear end 15" wheel I'm getting 18 to 20 MPG on the freeway I drive it daily I can go a full week on a tank of gas

[kfreeman1966]

Thanks guys, I knew that posting here would give me some answers. Ya'll have been a real help.

Thanks so much,

Keith

[samuellg1977]

Originally Posted by Greshampiglet

I Have a Crate motor 350 and a 700R4 anda 3.54 rear end 15" wheel I'm getting 18 to 20 MPG on the freeway I drive it daily I can go a full week on a tank of gas

Same setup here - except 3.08 gears... Ain't it nice?!?!?!

Sam

[Captainfab]

The correct gear ratio is also going to depend on the rear tire size. The higher the gear ratio doesn't automatically mean better mpg's with the lower rpm's. The engine needs to run in it's 'sweet spot' for best efficiency. What gears does the truck currently have?