If changing to a carb, use a dual-plane, high-rise intake manifold such as the Edelbrock Performer RPM Vortec or the equivalent Weiand Stealth intake. You'll make more power and torque throughout the rpm range with this manifold than you will with a low-rise unit. The RPM was mis-named. It should have been called the Street Max. Think of it as a Z28 high-rise. This is my opinion only, but it is shared by others and backed up by dozens of DynoSim pulls.