Mopar ECU Orange Box Strange Issues

Here's a good one hope someone can help me with. Got a 67 Dart with the
Orange Mopar electonic ignition on it. Always have had trouble with no spark sometimes starting it - both with the 273 it had and now the 360.
Put in a rebuilt distributor from Autozone - ran fine for a while. Pulled the coil wire off the distrib and found out after you crank it a short while, the spark quits.
From this web site I see that a lot of people have had issues with the Orange ECU so went to AutoZone and got it's replacement which is CR109. Did the crank test and the spark doesn't go away - I thought, problem solved!!! Starts real nice. Took it down the road and it won't
rev up, think it's dieing around 3-4k. So, went to AutoZone and got
another ECU, hooked it up, same thing. Played around with the distrib
relutor gap, still woundn't rev up. Hooked up the Orange box again(has 4 pins), revs fine. Anyone got any ideas??? CR109 is the correct Orange Box replacement, isn't it? Seems to be all they sell anyway.