I have had them stacked for a while now. Pup on level 2(75hp) and the edge on level 1 or 2 of 5..Haven't had any problems. Runs great. No bursting since dealer flashed the ECU..Oh yeah I have the boost stick installed also.
Have to launch in 4 wheel drive, 2 wheel is useless even when playing with someone at stop light. spins till it shifts into 3rd.. Wasn't so with just the edge. you could floor it from a stand still and it would only spin a little at the top of 1st with my 285's.
You do pay for it a little with alot more timing rattle when cold (power pup). Sounds normal when warmed up though so I find my self letting it warm up alot longer in the cold mornings.