It's cut down from front to back..shortened. concaved on one side and convexed on the other. Thinned down because of that. .....an Allison torque tab is welded on.
It will help the handeling of most Allisons + get you some top end if you are set up for high speed runs..... Doubtfull if it will get you much added speed on a "true tournament boat"
Be very pickey as to WHO does it
I have only found one guy in this area who can do it and they don't crack or break.