I wanted to do it my self but didn't have the time so I took it to a tranny shop. it took me awhile to figure it out but it's great if I need them I have 6 gears. the hard part is when i'm going hard through the gears if I don't shift the tranny just right with the over drive it will drop down a gear instead of going up. the over drive shifts faster than the tranny. it gives me about 30 more horse and about 60 more ft lbs tourqe. cost was 3'000 but i'm worth it. they say it will handle 1500 hp. the down side is you have to change the fluid in them about every 2000 miles. but it's only 1 quart of dextron
