Need some help. I cant figure out why my motor is now only running on 6 cyl. I have a msd digital 6 and msd billet dist. I already checked the settings on the msd and it is set to 8 cyl. checked the plugs , wires and wire orientation (firing order) and everything checks out. The problem is the motor starts and cyl 1 and 2 arent firing. Any suggestions on what i can check? Oh I did look under the cap and everything there looks fine as well.

I went back to a regular HEI because my MSD kept killing spark plugs. I had to change them out on what seemed like a monthly basis. I'd check your plugs as a first measure, then I'd check the spark plug wires. Those are the two major players in a no-fire issue.