Which Carb/Intake Combo?

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.

As it is intended design. He will have more of a bone stock motor. 8.6:1 and a 256 cam. A Stealth?Really? Talk about a wasted intake. The engine itself will fall flat a little over 4K, so the SP2P is a match. But it will have tons of bottom end torque before it gets there. PERFECT truck engine.