This will retro fit to the 700r4 and is a great addition when adding big power or just looking to free up some extra hp. They run full roller bearings and you get rid of a parasitic washer that is a big drag on the trans so free hp here but most of all they hold way more power over a stock 4 pinions and the rear planet is actually lightened and set for better lube. They run 300 each new that is 300 on front and 300 on the rear and mine are low mileage take outs from when I worked for gm both sets are out of h2 hummers. They are very hard to find used and the few times I saw them listed on ebay they were close to new price for the used ones. I am asking 300 shipped for the set so saving 300 bucks over getting them new and I have checked them for any flaws and if had them I wouldnt sell them. Make this part of your next trans build and you will be very happy and have piece of mind. I have even installed all new bushings so the wear points are new. consider trades also I am in need of some 60lbs injectors or around that. I have 42 and maxing them out at 10 lbs of boost and one set is going to pay for them anyway. So if easier to buy with a credit card which I cannot take then trade will be up for that also as 60 lbs run around 300 bucks depending on manufacture. My 42 lbs are lucas and very very low miles and will be selling them off or trade for 60s. So 300 shipped or trades considered....