400 block would be better IMO. Mine has Indy alum. caps, hughes girdle, alum. rods. I think rpm, and detonation are what kill blocks not the power. (I'm sure they have a limit but I have not reached it yet) I have made hundreds of passes with this block with 300hp of nitrous and 30-35 passes with 15-16 lbs with turbo, and have just a few weeks ago made about 10 dyno pulls with 25 lbs with my 101mm.