Drivetrain durability ?'s

i have a question or two about the evo 8/9's trannies. my old dsm always gave me problems with the tranny and i was wondering if any1 with evo's have the same problems? i will drag ocassionaly and plan to road-course once or twice this summer. i've read that the stock clutch is good to about 15k but what about the tranny/transfer case? thank you guys again for all your help.

Silva