I have 3 superchargers sitting here and I am trying to determine the difference between them. I know one is a Gen V since it is off of a 2005 GTP but I have a engine and transmission from a 97 GTP. The 97 had its engine replaced at some point in time and it is very clean. The supercharger on the L67 engine in my 99 GTP has a bolt on the end of the pulley. The pulley on the 97 GTP engine? is a press on and the pulley from L32 is press. What gives here and why are the pullies on my 99 and the 2000 GTP parts/builder car I have all bolt on?