I'd put my Money on cheap gasket failure: hence the loss of PSI in 3 thru 6.
pull the head off, take it back to the shop that worked it just to have them check it again.
if it's good, clean up your cylinders and piston surfaces, get an OEM gasket, reinstall.
This time use a tap / thread chase to clean out the head bolt holes in the block, make sure they are clean and free of obstruction. possibly get new head bolts.
depending on how much they took off the head, the bolts can indeed bottom out in the holes which has happened to a few MUD members. ensure the bolts are the right length, not too long. If the bottom out you cannot achieve correct clamping pressure on the head as the bolts bottom out into the block, yet your torque wrench will show that you reached the correct torque spec as you continue to twist the bolts.
Use a good torque wrench. Use the correct torque sequence. snug the head bit by bit, in that correct sequence.
follow the recommendations to re-torque the head after a warm up, then again after 50 miles, 100 miles, 250 miles, 1000 miles.
when you do this, just do one bolt at a time. don't loosen up the head, just one bolt at a time.
good luck
pull the head off, take it back to the shop that worked it just to have them check it again.
if it's good, clean up your cylinders and piston surfaces, get an OEM gasket, reinstall.
This time use a tap / thread chase to clean out the head bolt holes in the block, make sure they are clean and free of obstruction. possibly get new head bolts.
depending on how much they took off the head, the bolts can indeed bottom out in the holes which has happened to a few MUD members. ensure the bolts are the right length, not too long. If the bottom out you cannot achieve correct clamping pressure on the head as the bolts bottom out into the block, yet your torque wrench will show that you reached the correct torque spec as you continue to twist the bolts.
Use a good torque wrench. Use the correct torque sequence. snug the head bit by bit, in that correct sequence.
follow the recommendations to re-torque the head after a warm up, then again after 50 miles, 100 miles, 250 miles, 1000 miles.
when you do this, just do one bolt at a time. don't loosen up the head, just one bolt at a time.
good luck