I enquired about this a couple of years ago, if you wan to know more give brooklyn reditch a ring on 01527 521212, ask for roger in parts, he will tell you everything you need to know! from what I remember, it is a 91mm stroke crank, the sump is modded along with oil pick-ups to clear the extra throw, and it makes 440BHP and 450Lbs/ft but has a usable rev celing of approx 6000RPM