Spark Plug Gap?
 

What are the effects off a wider spark plug gap, as long as your ignition can handle it? Mileage, ride, etc.......

I heard that after a certain amount of gap that it can negativly affect the flame pattern, etc. Im unsure of this and my 67 still has them gapped at 80 i think. But thats with my all msd ignition and i havent even seen my 67 in hummmm6 months.

I just replaced my stock HEI coil with an Accel Coil and gapped the plugs at 60. They were at 45. It seems to run a lot smoother at idle now. I guess I will see if it effects my gas mileage up or down.

I don't have the answer ... just a comment on what I ran into.

I'm running HEI with R46SZ plugs gapped at .45 - pretty hot plug but it runs better. I had the R45 plugs and it was kinda rough, we gapped them at .60 with no change, and the plugs were kinda damp... went to the hotter R46SZ plug and have not had any problems... now I also haven't checked mileage but I'll get around to that.

if your gap is too wide it is hard on the secondary of your coil ...will shorten it's life a little...i have an MSD 6al setup and found.060 to be the best gap for me...