You want Mopar based parts? Hows this, 1972 340 block factory heads (cleaned up ports and decked for straightness), crank, and rods, 40 over O.E.M. replacement pistons (were in the engine when I got it so they could be 20 plus years old). Think about it, the block, crank, rods and heads are 38 years old. This motor pushed a '73 Duster to a 12.67 @ 107 WITHOUT tuning shifting at 6100 and can take more. Is that bad and fast in your opinion? I don't mean to tug my own blow horn but I think that is truly impressive for parts that old. I also agree that anything with offset valves, raised ports, etc is already to modified to compare to factory.