i would like to buy a complete set up 3rd member for the rear of my 94 runner.there is a big difference in price.850 4cyl and aroung 1250 for the 6cyl.randys r+p and others ive called say the 4 cyl will be fine in the rear.any 1st hand experience with this?

these are with detroit and 529s

 

Of the 5 wheeling trucks I've owned, only 1 has had a v6 rear.You'll be fine w/ the 4-cyl, but before shelling out the cash, I'd look into prices for individual parts and install into your existing diff. Could save some $$.

 

If you have ABS and want to keep it you will need a V6 housing with the ABS sensor Hole.

 

4cyl rear ends are strong, v6 rear ends are said to be about 20% stronger.
You could source the parts for yourself and save some cash as rockota suggested. If you are upgrading you might as well get the v6 unit especially if you plan on doing some serious wheeling.