Just bought some used Edelbrock RPM 340 heads... for my Magnum

why dont you just sell the heads and get the heads that you need?

I may end up doing that depending on how they look, however it would be a bit of a downgrade since it's not every day you come across Edelbrock SBM heads for $700 per pair and I can't afford more than that; I'd be stuck going back to iron EQs which was my initial plan anyway.