If it is an F3C it is an older head unit. That paticular blower was used alot in the NMRA Super Street Outlaw class. We had a few racers that ran them on 400-440 cubed small block Fords. On a true 10.5 at 3100 lbs they would run deep in the 7's at over 180 mph. The blower made great peak boost but would drop around 7-10 psi on the gear change (powerglide with an average drop of around 1200 rpm). Our current line up of F3's average more boost per run, make more peak boost, and depending on how tight your converter is you will see around 1-3 psi drop on the gear change. If you have any more questions or need some pricing please feel free to call me @ 913-645-0477.