i ordered a set of 4.88 yukon gears from dunks performance out in washington.
i told mike that i have an 87 4cyl 4runner, i assumed that takes a 7.5" ring gear, but failed to specify as no other 87 truck (except a turbo) takes any different size of ring gear.

they arrive today, but they are 8" gears for a 4cyl (i assume for an 85 or older truck ). i called him up and he said that the 7.5 were only for 2wd trucks, and that id be all set with what i had.

so im kind of turned around-ive read that all differentials essentially take an 8" ring, but it all depends on pinion bearing distance and shims. it is covered in this:

http://www.pirate4x4.com/forum/showthread.php?t=228681&highlight=ring+gear+size+4runner

-so i was just wondering if anyone could confirm if i can use what i have or am i going to ups tomorrow to mail them back?

thanks in advance.

You have an 8" rear and 7.5" front ring and pinion. Check your VIN plate to see if its a 4- or 6-cyl 3rd member in back:
Link to how to determine what type of 3rd member you have...

its a 3 fin third member so it is a 4cyl.

so i have two sets of 8" ring gears in the box, and only the rear will take that size, the other one needs to be a 7.5" right?

or i am all set? i really dont want to have the axles pulled out of the chunk and have that slow look of "awwww crap" come over my face.

thanks.

I'm pretty sure the front is a 7.5 also. You can pull the front 3rd member without pulling the axles out. I have done this with mine before, and drove around for a few weeks without it in. This way you can see for yourself without being unable to drive. You need to support the axle shafts, and not let them just hang down. I supported mine with some very big zip ties.

sounds like Dunk sent you ring and pinions for 79~85 4x4 Yotas......the pinion is slightly different for 86~95 models so I suspect you need to send both of them back.....get an 8" r/p for 86~95 model(engine size not important)......and a 7.5" r/p for similar 86~95.
You "can" use one of those 8 inchers that he sent you for your rear....BUT since that is an early model pinion most likely, then you will also need an early model 79~85 inner pinion bearing to make it work.
I think it's easier to just send em both back.