My first guess is that the valves are set too tight. On your #1 cylinder with both lifters down back off the adjusting nut until the rocker arm is barely loose. It should be set about 1/2 turn down from that for initial startup, then tighten them after the engine is running. Better for them to be a little loose than too tight, especially during cam break-in.


Fred
52 3600
69 C-10