We need a after market performance engine section.
 

Trying to figure out what gap to use on new plugs. 598ci 10.5/1 compression single 1050 carb MSD 6M-2 ignition box. The engine came to me with Autolite 3922 plugs and ran great and started great so that's what's going back. I know some one will say a diffrent plug would be better but it worked great with this set up. Just need to figure out the gap. Contacted MSD, they told me to contact the engine builder. Well great they are no longer in buisness.

Thanks

For MSD or Crane ignition systems we set the plugs at .045