Ring and Pinion questions???

I have been going thru the forum looking up information on ring and pinions for my truck. I have an 87 with the 4 cyl so it should be the 8" rear end and the 7.5" front end. My truck should be stock gear ratios 3.73 IIRC and I would really like to get some performance back after installing bigger tires (I am also hoping this might help with the engine overheat issue a tad). Preferably I am looking for 4.22 ratios. From my reading they are most common in the Montero's, most of which in the junk yards here have some combination of v6/auto trans and are newer which means 8" front end. 4cyl trucks and montys are hard to come by especially the older ones. So my question is will the newer front differential housings bolt into the older trucks? also rear end compatibility???

Thanks Mike.

the front diffs are 8" also, but are different than the rear diff. You can use the lsd from a starquest rear in the front diff of your truck, and the 4.22s will bolt to the carrier. The 4.22 gears were also available in the high trim 4x4 trucks. You want the gears from a 1st gen Montero 87 to 91 - they will fit the truck axles.

So the front diff on the 4cyl trucks are 8"??? I thought they were smaller based on the info I got from the forum here http://www.mightyram50.net/vbulletin...ion:Gear+Ratio The first gen Monteros are just about as hard to find here as the 4x4 trucks, no chance the ring and pinion from the second gen Monteros will fit at all? I am not really looking for a locker or LSD at this point in time, Just want to get some use out of 5th gear right now. I have been driving the truck back and forth to work and with the tires I have on it right now 5th gear is about as worthless as lips on a turd. Maybe in the future I will look into some form of locker or LSD but for now the truck is suppose to go to my son once it is done and I am not so sure it will see much off-roading, he doesn't seam to be all that much interested in going out to play if you know what I mean.

The front diffs may be the same, the rears are 9" on the 2nd gen.

And from what I have read the complete rear axle assembly from the 2gen Monteros are 4 inches wider than the MM.

the Montero sport rear axle is the same width as a MMM - it is the same as a L200, but with a shorter frame - running gear is the same. Many of the Montero sports have 4.22 gears.

So then If the front diff on the Montero sport is an 8inch like the MM then it could be possible to take the front ring/pinion and complete rear axle assembly from a sport and swap it over... Only thing I can think that will be an issue is whether or not the montero's axle in leaf over or leaf under.

Guess I need to take a trip to the JY and do a little research.