Roto-Master Turbosonic Kit (i.e. Accel) manifold is a nice way to go if the compressor housing isn't too large. The flow rate/diameter of the compressor will determine if a "lifting" spacer is needed. Original 1970's SBC 350 turbo kits were for "smog" motors and used a small diameter compressor to bump up horse power from 195 to 325 hp. If your car is already at/over 300 hp a larger compressor will (likely) be needed. A TO4R 60-1 should produce approx 550 HP in good installation since it supports 57 lbs/minute. I have one, but it needs a spacer to raise up the turbo since the compressor housing will contact the valve cover.