Powerglide

I have been running a glide at that level for about 18 years now. I use the 6 clutch upgrade in the stock drum (it holds up great), you need a good preferably 300M input, and turbo spline (if not it will break), and a good planetary, stock 1.76 can hold up for a long time but most of the time a couple or three years does them in. I have a straight cut 1.80 (it holds up great). You need 5 clutches in reverse and I use waffled material to set trans-brake crisply. I also use the billet low servo (optional) and dual teflon seal is best choice there. I like the Coan pro brake with stock reverse piston return springs, single drilled case also makes it easier. Good luck.
The Jegs part number for the 6 clutch piston is 206-COA-12826, thats for 6 stock thickness .100" clutches, I always liked sticking with the .100" clutches, they are more robust than the thin ones. Also you have to have a steel clutch hub for high gear if that's not assumed already.