I appreciate some of the thoughts and the time it's taken to repy.
Here are some new number to chew on. It took some time to dig out an old transmission out of storage and get it all fabbed up to spin the engine over, so I apologize for the couple days of delay.
With no carb installed (no air intake resistance) the cylinder pressures were between 171 - 173 psi. This is with a moderately to slow turning of the engine. Had to use a jumper pack and two chargers to spin it fast enough to get what I felt were accurate numbers.
I spoke to 440 source, and they were adamant that I was given the correct pistons. They said they would have caught it when they went to balance them, as it wouldn't have balanced correctly, not to mention they would have noticed their in-stock product counts would have been off. He felt very strongly that the cam timing was off four degree's. He says they regularly see my combo in the 625hp range and felt by adding the four degrees of timing, I'd get it. I tore the shop apart and couldn't locate the scratch paper I wrote my notes on when I degreed the cam, the kids helped clean a bunch, I'm guess it was tossed by mistake. I do remember lining it up dot to dot, and the lift and duration were right on, but not the exact numbers. I think my next step is to do what some here have said and what 440 source said, pull the water pump and timing cover and check the cam timing and add four degrees.
But just because I went through all the hassle, here are some photos of the pistons too.
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