Well boys, this might be the straw that breaks my back.
Everything is back installed 100% and fluids filled. New JE ProSeals + 1 new (used) ARP 2000, torqued 30-60-90. Had no problems there.
Started doing a coolant pressure test tonight and everything was looking fine, she was holding 15-16psi for about 10 minutes (within spec). Then I peaked underneath.....
Leaking from brand new HG's, at only 15psi, AND I DIDN'T EVEN START IT UP!!!
I'm 99.9% positive the heads aren't warped because;
1) they were decked <5,000miles ago and this is only a weekend warrior hasn't been tracked,
2) even tho I don't have a machinists straight edge, using feeler gauges and 2 diff rulers, I couldn't even fit the thinnest gauge (.0015") in ANYWHERE, and the warping limit spec is .0014". Sliding the rulers left and right, flipping them upside-down, and all other configurations to rule out the rulers being warped.
3) I wasn't having this problem with the old HG's. I may have been pressurizing the coolant with combustion gases, but never straight leaking coolant out the HG's.
I'm really, really hoping 1 of you guys are gonna call me an idiot, with an explanation like "you idiot! you need to heat cycle the HG's at least once, to allow them to expand to properly seal!!" or something along those lines.