I'm running an MSD 6A without any problems.
I've heard that the multiple sparks can help with emissions........
What gap are you running on the plugs? You can go larger with the MSD (.044)
Also, some low readings with compression are due to the compression tester. The valve is a tire valve, and it takes some pressure to open them. I've had compression gauges read 25lbs low until I found a looser tire valve (hook up to your air compressor to test)
i am running the plugs at .044 now with the same MSD 6A. I wasn't too worried about compression being an issue because of how close they are and the tester is pretty old so im sure its a little off. I was just glad not to see one way off.
