I made 613whp on a stock t-case and never had an issue. I would not expect it to last forever at that power level but it will go for a while. As for a boost controller a lot of guys like the 3 port solenoids so that they can control the torque curve better especially on the stock block. Speed density is supposed to free up some hp and help drivability. Im currently converting to speed density aswell.

 

stock t-case is quite durable, just have to take care of it. Keep a close eye on the fluid level, change the fluid religiously, and keep the drivetrain shock (hard launches from a standstill) to a minimum, and you should be just fine.

 

Clutch choices are tricky. I've been doing a lot of research and it seems as some of the Exedy units having trouble. I made 390WHP on stock placement GTX3071 and had to stop tuning as it started slipping on the dyno.

 

Clutch choices are pretty straightforward for this power level-

Comp stage 2, either sprung or unsprung, race as needed (example of how it shifts)-

 

Thats my setup minus the upgraded turbo.