re-gearing

[sadystikal1]

would 5:13 gears be way overkill on my bronco or would 4:88s get the job more than done. got 35's on a 7 inch lift on an 84.

 

[Stubby1971]

yes- that seems a little short- I've been told that 4.56 gears would be ideal on a 9" lift with 37" tires- I run a 4.88 gear now and it really doesn't work on the street- The truck is screaming at 55-60 mph- I'm not sure what the best gear is for a 35" tire, but I know if you want to drive it on the street you may want to think about a 4.11

 

[Yardape]

4.56 would be ideal for 35's. 4.88 would definately get the job more than done.

 

[sadystikal1]

so a 4:88 would more than get the job done but would it make it totally unstreetable or just not above 50?

 

[Roadkill]

Here is a link to a chart from 4Wheel Parts that you may find usefull. It's not ford specific but it will give you an idea of what what engine speeds you can expect with different ratios.

http://www.4wheelparts.com/gear_ratio.html

I'm not sure what you goal is, but to maximize fuel economy and make the truck perform the way it did before the larger tires, you will want to get the engine rpm at a given speed close as possible to where it was before the larger tires. If you want to smoke the tires and be super quick off the line, you will want a bigger number, but you will lose fuel economy and the engine will be screaming at highway speeds. I plan to go with 4.11 when I put the 35's on to bring it nearly back to where it was from the factory. (I outgrew tire-smoking starts years ago, but I sill like to watch others do it /emoticons/[email protected] 2x" width="20" height="20" /> )

 

[sadystikal1]

well it looks as if a freind of mine is going to sell me a solid front dana 44 and 9in rear with disk brakes a detroit and 4:88 gears installed for 500 i am going to take him up on it, will the brake fittings be the same and plug right in or do i need to modify?