May as well go with a 4.5" stroker, for more low end torque, while maintaining a smooth "sleeper" idle. With the correct, modified parts, including a roller cam, one of these should make 500hp + and maybe 600ft lbs of torque ?--and do it all below 5000rpm.
SMI can build you a monster Q-jet, to match the power level. They advertise 'em up to 900cfm.
Can squeeze a little more out of it by going with more compression. But, to do that, you'll need more octane, either thru a mixture of race gas, Torco octane booster, or E-85.
https://www.amazon.com/Torco-Acceler.../dp/B004ZO3VN0
But, with this kind of torque, you'll need to beef up everything behind the engine.
The guys who build the stock appearing, small street tire, type cars, have all sorts of tricks you can use. They do all kinds of porting to stock logs, and everything else that can be hogged out to increase performance. They also know all the tricks to hooking the power to the ground, with hard narrow street tires. The ET's they are running are unbelievable.
http://www.fastraces.org/
https://www.facebook.com/FASTRacingSeries/
So, if you can tap into some of the tricks they use, you can more easily reach your goals. There are probably some guys who post on this site who can share some of these tricks with you.
