Trick Flow SBM Heads

How much power do aluminum heads pick up on a 340 that already have the "x" heads with 2.02/1.60 size valves?

Loaded question. It's everything that will surround the heads which will reward you the money spent.... You would have to spill your beans as to the setup, be ready for feedback, and bust out the wallet. It's the only head at this point that will most likely get you something to bolt on OOTB but even then there is still no guarantee.....

JW