Mopar electronic conversion fires 4 cylinder only

Prior to installing in the car, it was set up and run and tuned on a test stand, same distributor and timing using test stand wiring, and ran great. I have about an hour or more of run time on the car in the shop and it was running fine, so firing order is OK. Nothing else was changed. The car has a Holley electric pump and Speed Demon 850 on a Street Dominator intake. I checked cylinder #2 and no spark. When the car did start and ran poorly the 2,4,6,8,side header stayed cold to touch. 1,3,5,7 all hot.