[PeteF]

I installed a Paxton on my '66 Shelby GT350 mustang, which had 10:1 compression. The Holley carb had to be rejetted slightly richer, and replaced the brass floats with (nitrofill ?) plastic ones to prevent them from collapsing under boost. I had severe pinging on acceleration, and had to add a ping sensor and electronic spark retard box (made by Carter, I think) which retarded the spark up to 15 degrees when pinging was sensed. The boost was only about 5 1/2 psi, but the car was very strong. I always felt I was giving up horsepower by retarding the spark, but didn't want to tear the engine apart to lower the compression. If I had it to do over again, I would build the motor with lower compression, or just stay naturally aspirated. Good luck