Fresh 360 will not runn

I did an R & R on an engine a while back & couldn't get it to start. Turned out that I hadn't tightened a bolt that grounded a wire from the wiring harness to the block. Don't know about the adjustable rocker thing. If the machine shop said you needed them, they could be right. Did you use a big cam? Did you do any milling of the block or heads? Did the lifters seem to preload as you tightened the valve gear?