I have a 94 SS clone that has all the goodies and just replaced the opti with a MSD unit and since I did it seems to chug at driving speeds (casual driving). I put my scanner on it just to check the timing and it was 38 deg. advanced . WTF?? Also with the AC Declo unit I was running 12.69 at 108 and now the best I could muster was 13.4 at 105. What the heck is going on??

 

The MSD has a really poor track record and if you messed up the timing adjustment it would NOT be reflected in the scanner timing display.

You could fab up a timing pointer, get a keyed hub and a degreed balancer, then put a timing light to it to verify the timing adjuster is set right, or you could put a fresh cap and rotor on the old delco base like you should have in the first place.

 

The MSD distributer has a timing ADJ screw on the top of it doesnt it??? I think it goes to 7 degrees...my buddy had a problem when we installed his and it came out to be a faulty coolant temp sensor.