Hammer has the Procharger with the intercooler. His car is freaking fast. The only down side that I have seen with it so far is that you have all kinds of tubing in the front of the car, plus the intercooler. Installation would be alot more complex and there are more things to potencially go wrong.
From personal experience however, the performance is kick a$$, as I'm sure a few shocked LS1 owners will also atest to
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1995 Mustang GT