Which intake manifold
Get some head work done first and then slap a new intake when you are installing the heads. You can find ls2s for cheap. Even unported work make a worthy difference. A FAST intake would be great add on then. You will prob need bigger injectors. Some have done cams and had over 100% duty cycle registered but still had no fuel feeding issues. With any intake but a ls1, you need the coolant x-over pipe and rear block offs. I have some used ones for sale if you need?
But it didn't mention anything but haven't been on dyno yet, do you have at least a mail order tune or tune of some sorts? Grab a 85mm MAF before you get it tuned. You cannot just throw 1 on after a tune. I have some of those for sale with harness connector to wire it up as well.
Good luck





