[Alex Evonosky]

Not knowing the WHOLE story on this engine: Stock heads, type of cam, correct push rods fot the type of head, and valve, solid or hyd. lifters, was the engine assembled correctly, or maybe the ring gaps may be incorrect.
If all the above is correct,
remove the #1 plug,
be sure the #1 piston is at the top (on the compression stroke)
pull the dist and re install so the rotor is pointing to the #1 wire.
follow the rotation, and check each wire to be sure they are all in the correct firing order.