Help with sb combo

m putting a mild 340 back together to hopefully run this coming season. Im torn between what intake and cam I should use. Car will be raced not street driven, only the occasional car show.

340 - .30 around 12 ish comp
TRW pistons
Worked stock 340 rods
318 crank
J-heads milled with a lil work and large valves
904 w/9 in conv stalls around 4500+ on fb
750 Holley

Before anyone says anything about getting new pistons/rods, that isnt an option. Im using what I have unless something ends up being broke. that being said what intake and cam do you all recommend? A few options Im considering

296/ .557 cam
296-298 . 577 int .555 ex cam
or suggestions??

Mopar single plane or Air Gap??

Here is my question.

318 crank with stock 340 rods and piston?
are they dome or flat top pistons?
2 valve or 4 valve piston top.

IF you have a "light" crank(318 ) there is, or will be, a lot of mallory ($$$)metal in it. If you ballance/d it.
Before anyone says anything about getting new pistons/rods, that isnt an option.

I think, you might want to consider it......................