I have had my 1500 head machined. New seats and guides ,.003 surfaced. I put the rocker arm on and I have 2 of the rockers that will not adjust when the head is mounted on the block. The adjustment screws are all the way up and the 2 rockers are tight. The lifters and rods look like they are in the correct alinement. What can I do? Tom Gunderson, 1500 mga rst