Valve Lash Adjustment

Check them now. You don't have to get it running to do that. That way you can find out How to get it running again. One (or more) of the plugs will clearly look different from the rest. This is most likely the bad cylinder(s). From there you can take the next easy diagnostic step of checking the pushrod. Good pushrods? Next would be most likely a faulty (collapsed ) lifter. Time to take the intake off. Etc..Just a first ( and easy) step in the process of finding the culprit. Good Luck!