So I have a 1997 q45 with some upgrades like body stiffening straight pipe and few other things but looking to get up to 500+ hp for less than 3k how and what would I need to do this.

Not gonna happen for less than $3K, or probably even $5k, unless you've got a supercharger/turbocharger lying around, a machine shop at your disposal, fab skills to put it all together, and tuning skills to make it run right. You're talking about nearly doubling the stock power level, which isn't going to happen without forced induction of some sort, and that's not going to be cheap to put together.