If it is the original engine you may not have the valves adjusted correctly. You have to have some clearance between the rocker & valve stem to get it started. If it has an engine with hydraulic lifters the lifters may be stuck in the old position & not compensating for the change.
Make sure #1 plug is firing on the # 1 comp. stroke. If #6 valves are opening & closing as the engine turns then the pointing of the rotor should be to the #1 term in the cap.
George
