That engine most likely has hydraulic lifters. Loose rockers indicate something is stuck, (like valve stems in the guides) or the rockers are way out of adjustment. Even with both valves fully closed, there shouldn't be any looseness between the rockers and the valve stems.
Jerry
I did adjust the valves myself after I put the head on the motor. Right now the #2 appears to be on compression stroke & the cylinder is up. The rockers are up & I can jiggle them, so they are loose. Problem is that I can’t turn the motor by hand.
