Help Wellcraft boat ummmmm

It's just not a v20, Model no. 186 ss/s yes i know it's not the type of boat you guy's boat with, but it has some unusal charastic's.

That is it is very fast and stable, i can run @ 60 mph and im under propped using a 4.3 efi motor and a 20p 4bl prop. Opp's that's a 22 pitch

They only made this boat for one year, does anyone know any facts on this boat? the speed is gps verified and im trying to fugure out why it seems to preform so well.