On my 1976 ford f-100 it has a three speed transmission, and the rear end I dont know but I am guessing a 4-10. Here is my problem, When its in 1st and take off it seems to be to high of a gear but once i shift to third and get up to speed it acts like it winds out like it has to low of a gear but in 1st it acts like its to high of a gear to take off in. So I was told to change the rear end to a different ratio. What gear ratio should I get I want something low enough to take off road bu will not wind out, I have a RPM guage but dont have the numbers on what the RPM is when it winds out. So my questions are what rearend should I look for and what should I look at for getting one, Someone told me to look at an older mustang. What types of rearends should I be looking for, I want something that I wont have to do laot of changing to I knoe finding the right thing that goes on the drive shaft is going to be hard. Thanks in advance.

 

What engine do you have in it ?
What is the code for the rear gear on the door tag ?


I would think 3.25's or 3.50's would be right.

 

Is it 2wd or 4wd, and what are the #s on the diff tag on the back bolt cover(if D44) or housing(9").
Also what engine, and tires do you have?
And what all do you use this truck for hauling, off roading, daily driver, work truck, mix of all?

 

It has a straight 6 in it, It has the origional size tires. I think I will try and find a 3.50 rearend. It is 2wd, It will be a combination of work truck/ offroad daily driver. I will have to check out the door tag about hte ratio, I will get back to you on it.

 

All right here are the only numbers I found on the door tag besides the VIN

GVWR 4800
GAWR Front 2680 Rear 2550

Are these the right numbers.

There is not a tag on the rearend itself. I am thinking its the origional.

 

There should be a number or number-letter code on the tag under axle.

 

are you talking about the tag on the door area?

 

Yes, door tag.
It should look close to this one.

http://www.clubfte.com/users/mil1ion...ruckCodes.html

 

My door tag isnt exactly the same, I tried to take a picture but my battery is dead, I got another number off the tag maybe its this.


FO296/RO562

Is this it?

 

So were those the right numbers?

 

I'd have to say no. The best way is to check the tag on the rear end bolt cover.
3.50 would be easy to get in a stock axle and swap, or just buy a ring and pinion and get a proffesional to install it(either 3.50 or 3.73), b/c it is going to be used as a real truck not just a cruiser so no less than 3.50.
I do about the same thing with mine and swapped the 3.07 ratio for a 3.50 gears and a LS(and I'm pretty happy about it)