HEI in Mopar ECU casing

Major Question! How in the world are you guys getting away with running the GM 8 pin module? I have 4 genuine GM 8 pin modules and every one of them add 10 degrees of advance at around 3500 rpm and make it detonate like crazy! Got to be more than a coincidence that 4 different 8 pin modules add this advance..are you guys sure yours isnt doing this also?