Pulled out the 7-1/4, narrowed my 8.8 this weekend and got the perches on. I set it in and was going to set the pinion angle but it just wasn't possible with the car in the air and i don't have the plates yet. So I just set the perches like a A body 8-3/4 and welded them on. If I need to shim for a lite bigger angle, it's no biggie.
I will say that these rear ends kick my ***! It's alot to wrastle solo