I replaced the head and had a valve job done. The engine starts just fine and after driving it about 30 miles and parking it then when trying to start it the next morning it won't start. Acts like the timing is out. Checked the timing chain and gears, they were in perfect order. The number one intake pushrod had come out of the rocker arm. I put the pushrod back in place and then drove it again about 30 miles and when tried to start it again the number two intake pushrod had come out of the rocker arm.