That sounds like a good call on the plugs. I was just being safe. The AR3934 crosses to a -8 NGK and the AR3935 crosses to a -7. I have not run many pump gas things. I use the ar3933 or 3934 for some of our alky stuff so I figured the 3934 would be safe to get close and maybe step up when it was close. Sounds like I may have been "extra" safe.I didn't do the cross reference to check, but I would probably start it at an NGK 7 heat range.
I always ran a .018" gap with my turbo engine, always started well (by the way, I did not run 7's with the blown or turbo engines I had)