Competition has always been the driving force in development. It's good that people need more power, need to be the best, need this, need that.
I'd like to think that I've seen plenty of msp's in my day and I don't recall ever seeing one with 400whp. Are they out there? probably. 500whp? never. 600whp? I had a dream once that mine did!
To the orginal poster, the block will theoretically hold it, but there is a good chance that you'll repeatedly blow the head gasket. Tranny's have been known to burn out with 250whp +. Keep that in mind as well. You're best bet is to look to other people's mods of things other than the block. Shave a few things off here, open up the pipes there and you'll add up 5hp here and 5hp there. That is you're best bet to get a "fast" car. There's no reason to put all the power into the block alone. It would be like putting a reactor in there, but when it goes boom, you take out twenty city blocks.
Another thing to think about is weight reduction. As others have already posted, MSP's are already lighter than most. You don't need 500whp to beat another 500whp car.
If you're doing a custom tranny (as I would assume with 600whp goal), think about changing the ratio's. Make 1st longer, otherwise you'll just sit at the light spinning you're tires all day long. Shorten fourth, that's where most "real" cars beat us (think supra).
Oh, and good luck with it! Plan for about 20-25k to put into it. And then another 15k+ for a car that you will be able to drive regularly.
Keep us informed with it's development.
