I am getting ready to drop a recently built 428 CJ into my 67 GT-500. One question I have is what should the Spark Plug Gap be? I am running champion plugs recommended by Edelbrock in their aluminum heads with a Blue Thunder single four intake and 750 Holley with vac secondaries. The motor will also be equipped with FPA Tri Y's and I have a Pertronix ignition in the stock distributor and Pertronix coil along with 8.8 spark plug wires. I currently have the gap set at 37, stock is 35. Welcome all related input.