Combination 7260 & 1350 u joint

7260s are for slantys and such, lol.
For more serious engines; and with 8.75 rears, as soon as you upgrade your rear traction issues, you may be spitting them out. With a manual trans, I highly recommend to upgrade your pinion yoke to at least a 7290; and then you are good to ~400hp on the street with street tires.
There are two 7290 rear diff yokes available, with the only differences being the spline counts; coarse and fine. Coarse is 10 splines. Get whichever matches your pinion. If you keep the 7260 at the back, keep your AAA card up to date; cuz that cross-pin is pretty delicate-looking.
There is a 1350 to 7290 adapter U-joint available; I run one, and since I put it there, I haven't had any more trouble.