Jack, yes a 390 cfm 4 barrel vacuum secondary would be worth a try, cause when you calculate the cfm @ 1.5 the 500 2 barrel is more like 357 cfm.
Doug, i would sugest a 8.5 power valve in your 4412, not the 5.0 valve. The 8.5 richens up the part throttle mixture without over richening the full throttle mixture from too large a main jet.
Just a thought, Bill
Doug, i would sugest a 8.5 power valve in your 4412, not the 5.0 valve. The 8.5 richens up the part throttle mixture without over richening the full throttle mixture from too large a main jet.
Just a thought, Bill