Check your timing to be sure the marks didn't move, TDC on compression stroke, after you put the belt on.
Your hydraulic lifters seem firm when you try to push down on each one - not soft or spongy?
It looks like you didn't have your original head reworked but rather got a used reworked head with unknown mileage?
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?