Most of us have had the pully and the tune for around 600 rwhp, however all our dyno runs show the hp and torque lines to be rather jagged above 4500 rpm. They attribute it to the boost blowing out the spark. The GT Guys and Jerry gapped the plugs and did the tune so we went with the best.
After taking with one of the techs at Kenne Bell he said they see it all the time with the GT's and it could be solved with the Boost-A Spark. I spoke with the terrific techs at Team Ford in Marietta and they said they would like to see if anyone else had some experience with it.
Flash