318 cuts out when revving
If you hot wired the system direct to battery and you are sure it's getting power there's only three things I can think of..........
Somehow the Pertronix system has a problem
The distributor is worn out and stopping the Pertronix from triggering........shaft play, etc
Or a bad coil
The only other factor is "what all" as in "what else" do you have hooked to the coil..........a tach? UNHOOK it. Radio noise capacitor / condenser? UNHOOK it. Get it down to only the distributor, Pertronix, and coil.
By the way check your "hot wire" I've had trouble before with bad alligator clip leads, AKA radio shack