Re: Brodix 2X head, 340 intake runner for my 540 motor?
The 2X head needs some work in unported form. Regardless of what they advertise the best flow numbers you are going to see will be in the 340 range on the intake. With porting or a CNC program you can get the intakes up to about 390-400 without breaking the bank.
The exhaust needs the most work and can show the most gains. You can pick up substanial flow with a well ported exhaust. The chambers also need some work that will improve mid-lift flow and the transition from the seat into the chamber.
That being said, if you can't make enough power with dual 76 turbo's (regardless of the head as long as it is decent) you have a serious problem with something besides the induction system. The better the head the lower the boost number will be.
I would get a good set of heads already CNC such a BMF, AFR, RFD, or Chapman to name a few. The CNC program is well spent considering the power per dollar you will gain. In your case since you are going to blow it in if the head is a little larger than the conventional suck it in you will be fine.
I have run 4.70's (1/8 mile) naturally aspirated with a set of 2X heads I ported on a 1850 lb
dragster with a 557 BBC. Not too bad but if I had to buy a set of heads today they would not be my choice.