Hard question, but I have read on other forums that 500HP max before failure, I have seen some guys with 30K -40K on there odometers and still running strong with 480HP daily driver and week end racers...
It's all subjective. You could easily pop the block open with 400rwhp and a canned tune or be fairly safe at 500rwhp if it is tuned by a pro that actually understands the tables the tuning requires.
i have been running a v2-sq set up severely detuned to 453@ the wheels and 429tq i have had no issues. all tuners say safe range is 45-460 at the wheels. i am upgrading the internals due to this i want big boy horsepower now
I'm in the 490 rwhp range acording to my weight and et's
I haven't even been on the dyno yet although I've run over 150 1/4 mile passes with a best of 11.427 @ 119.92
I 'm running the Saleen S/C with the JDM stage II kit at 10 psi.
JDM has done 500+ of these kits that they are virtually spot on without even hitting the dyno.
I'm in the process of building a motor for bigger numbers and long term reliability even though I have no problems so far.