I have a 1990 Toyota pickup with a 7.5 in differential I recently was forced to swap out the size of tires that I have and and I can't go back to the previous size. The tires that I have now prevent me from going into 5th gear I would like to re-gear the differentials but and I'm having an issue finding the right gear ratio I'm looking for either a 4.10 which is a little bit higher than I need. or a 4.07. does anyone have any good recommendations as to where to get these gears from for a reasonable price?

 

Is it a 4x4 truck? The 7 1/2" for the front IFS diff? The rear an 8"?

Most of these trucks came stock with a 4.10 ratio if you had the manual trans and 4.30 (I think) for the auto trans.

What size tires do you have now?

On an 88 truck I had and my son's 91 the stock gears were 4.10's. We ran 4.56's when we went to 31" tires and 5.29's with 35's. (4.88'S would have worked with the 35's for my V6)

IF you are 2wd, obviously none of what I said applies.

 

It is two-wheel drive. For all intents and purposes I'm running the '30s and stock gear ratio is 3.583

 

I just took a quick look at East Coast Gear supply and they do offer some 7 1/2" gear sets but nothing in the ratio you are looking for. I thought maybe swapping in a complete 8" axle from a 4x4 truck if it's the same width but you'd end up with 6 lug bolt pattern. I have an IFS width rear axle (1988 4x4) I can measure that has a stock open 4.10 8" diff in it if it would help. IDK if the 2WD axles with brakes would slide in or bolt up to the flange? Easy solution if they would. PM me if you need measurements.

Maybe give ECGS a call or any other differential specialty shop.