my 408 build

It should make around 450hp with J's and close to 500 with the RHS heads like Brian does and a better carb on it, like a 950hp.

I had a friend with a 340 that Brian at IMM did. Eddy heads with light clean up, same cam/compression, victor intake, 1 5/8 step headers and 950hp. Made 455hp

The RHS heads you plan on using are as good or better than the eddies on that engine. IMO, an Air Gap would be a better intake.

It should run low 12's, and really should go in the 11's at around 115. Dat's one heavy swinger!