if i were to be able to get RPM heads it sure would be nice to be able to run the springs on them. i cant find any information about the springs other than 600 lift max. how much cam can be run with out of the box heads?
I ran the 292/292/.508 FTH with 1.6 arms so .542 lift
later
I ran a 270/276 Hughes FTH at .538/.549
Both of these went to 7000 and beyond at 1/2 turn preload on the Hughes circliped lifters.
Btw the alloy heads worked awesome at 195psi on pumpgas.