I have a '94 sc in the shop and I just got the motor swaped out. However the problem existed before the new long block. Ok so the car runs and drives fine but when under boost sometimes it will go to about 5psi and hang there for about another 2,000rpms. Then the boost will just kick and it will peg to 14psi right away. Sometimes there is no lag at all. Again I got a newer long block (less than 20,000) and my problem existed before the swap. Could it be a slipping belt?