well my car made 650 on a mustan dyno at 35psi, and this is a 100% new clutch 100 maybe 200 miles, it started slipping at the BR shootout last year first pass. I turned the boost down to 29psi and it was much better it still went 9.90 but it was slipping a bit in 4th gear, as soon as the boost went past 30psi it was all over.
The clutch that's in there now still feels ok but I don't think it will make it past 35 psi safely. I'm sure if you get a 8 leg clutch and a 6 puck gear drives you probably much better than me. My car with me in it is about 3300lbs, 400 lbs is huge so you should be fine, you probably be fine with the 8 puck discs.

 

Sweet thanks for the advice. When I rebuild it...I'll go for the 6 puck. Thanks for the advice! I'd like to see a few more vids of your Evo going down the track.

 

I plan on going to the track next week, I need to work on my 60ft. My talon on the QTP cut mid 1.3s and on the evo is mid 1.6s I have to spend some time with the suspension.