I think for a street motor with your intended use, you have 4 intakes to choose from. The RPM, the Six Pack, 440-2D and Holley SD. The RPM and 6 pack will gas-out first, but can get you to 550 HP. Even on a 500 inch motor, 440-2D dual plane makes better low and midrange power over the Holley SD, but will make about the same up top too. They will support 600 HP.
I have all of these 4 intakes in my garage but haven't decided which one to use on my 500" build. I'd like to put the Indy 440-2d on the engine first but unfortunately it has some core shift (center ports are moved up on one bank and lower on the opposite side). Once I have the engine fully assembled (with heads) I can see how much rework is needed.
