Wow, i'm glad you have taste in cars... ha.
I think the problems with your trannies is you. How can I run my stock 4T65-HD to 150k with any problems on a modded GTP thats was race quiet a bit and flogged many times? I had no problems my only secret is dropping the pan every 20,000 miles, all I ran was Valvoline Dex3 and a Wix filter.