I am going to put a LS1 in by BMW M3 race car. What mods to a basic LS1 would I need to get around 420 - 450hp at the crank? I want to be able to rev the engine reliably to 6700 - 6800rpm. Because I may run slicks, I plan on fitting a dry sump.

 

That can be done easily. Heads and cam will get you 420-450 at the rear wheels....assuming you have a free flowing exhaust. You can do a pretty mild cam along with a good exhaust set-up to see that power leval at the crank. Might as well say it before everyone jumps on you, but you might want to check out the search button :p

 

420 at the crank isn't a big deal. 420 at the rear wheels isn't real hard to do either, if you have the money. All depends on your goals, and what you're willing to deal with/sacrifice. And if you have to pass emissions tests. A free flowing exhaust is a must, and with the M3 I must say, that shall be an interesting setup. With a Head/Cam setup, 420 to the rear wheels should be a peice of cake with a six speed setup.