I'm startung to use 110 leaded racing fuel to contend with detonation now that I'm boostin 15psi....should I get colder plugs, I have 7's right now, will they foul out easily?

 

You should be running 9's in all positions so they don't hold as much heat, this will help prevent detonation. They will fould out fairly often, I know because my setup is close to yours. Running the colder plugs will probably help more with detonation than the higher octane gas, though I also run a few gallons when I go to the track.

Nick