340 Max HP Potential with X/J heads?

No, I'm the go fast type and dont care that my engine doesn't look stock. This engine is going to have a .575 lift cam, Victor intake, a Holley carb and most likely headers so it's not going to fool anyone into thinking it's stock. I could understand if it was a FAST type build.

My advice to the OP is to call some good head guys and pick their brains, they'll give him the pros and cons of both types heads.

Is this a street or race deal? If it's a street deal with iron heads and 11.0-1 what gas is the OP planning on running?

And I'll move along when I'm ready.
It's a street race, full weight, restoration running pump gas, 4.30 diff, reverse manual 904, ss springs, street slicks, stepped tti's, full length dual 3" out the back