Designed to drive HEI module plate...

That plate isn't your issue. I've been running mine without a single issue here in Oklahoma. It gets pretty hot here and I even took a 2 hour trip in 100 degree weather without a problem. The car sat for about 3 hours and then made the 2 hour trip home. I'm using an MSD coil and a stock mopar distributor. The HEI module is an Accel 4 pin module. I doubt it adds any power or does anything special, I just thought it was probably better quality than most.