OPINION ON DISTRIBUTOR

I HAVE A 8388 MSD THAT HAS VAC ADVANCE.THE VAC IS NON ADJUSTABLE.IT PUTS 20 DEGREES TIMING AT THE CRANK WHICH I FEEL IS TO MUCH. I DO NOT WANT TO WELD OR PUT A SCREW IN THE PLATE AFRAID IT MIGHT COME LOOSE AND PUT TO MUCH TIMING IN THE ENGINE.I WAS CONSIDERING GOING TO A PROTRONIX DIST WHICH YOU CAN GET AN ADJUSTABLE VAC ASSEMBLY.ANYONE RUNNING A PROTRONIX AND HOW DO THEY COMPARE TO A MSD