This is from GNTTYPE website on a recipe build up.
"... replace the plugs with AC R43TS plugs gapped at 0.035 for 13 to 14 second cars and AC R42TS plugs gapped for 0.035" for 12 second and faster cars."
Use the CR plugs. They are for commercial vehicles and they have a bigger electrode. I think they help handle the boost better, less knock,IMO. Picked up 6 at Champion Auto for $10. Good investment.