The first turbo car I had a ride in was a 240Z in 90' with a blow through 4 barrel. It was fast enough to make me forget about the tripple carbs/cam/pistons I was saving for. I was turbo'd a few months later. He used a Holley blue pump and regulator running boost to the vent port on it. Run a Holley not a Carter, the accel pump is not covered by the plenum/bonet and will spray a little gas under boost . You could still run the stock turbo exhaust manifold and turbo but would have to get a real 4 barrel intake manifold, not one of the bolt on to the SU adapter ones, they won't clear the turbo.