You may have the Distributor time 180 degrees out. Verify when the #1 cylinder is on its compression stroke, and see where the distributor rotor is pointing. If it is pointing to the number 1 plug wire you should be ok, but if it is pointing at the #6 then the distributor is 180 out. If that is the case you can either remove and retime the distributor or swap the plug wires to the opposite side of the cap.