It probably wouldn't hurt to do a compression check on all cylinders before you swap/ disassemble anything. That might tell something. Did you happen to do a compression check on the old original head - maybe compare numbers also.
Plus I'm sure many would be curious what your compression numbers are now too.
Member of the Dropped Valve Seat Club.
Replaced #4 Piston, Rings, Rod+Bearings, AERA Re-Manufactured Cylinder Head and a light Hone. Then CLEANED the hell out of everything.
40k+ miles, now jinxed?