Check timing at slow idle, vacuum line unhooked. Set at about 14 degrees advanced if I remember correctly with the Z cam. Good way to set time without a light to get a rough setting, rev the engine steady, say 3000 rpm, move the dist. advanced to get best smoothest engine, back it off a bit. Worst case deal here, check for good rocker arm movement, maybe something destroyed the cam lobes... Sure hope not.