Leaking issues in my 200 4R - any gurus available?

I have a different question for you 200 guys. How much torque and HP are you putting thru your trannys? I want to get some user ideas before I have Lonnie build me one. I guess they're getting harder to get cores for and I don't want to be a year from now with a busted tranny that can't hold 500+ hp,and now way to replace it. I 'm gonna drive it a lot,not just weekends. I like not trashing the floor on an A body with to 2004R. Thanks.