I have an SP2P on a 318 with a cam and 600 cfm eddy carb and it falls flat on its face at 4,000 rpm. I bought the truck the way it is so I have no clue what cam is in it but it is definitely not stock. I would use either a Weiand Stealth or performer 318/360 on a mild build. The SP2P is more for a bone stock motor.
