The ribs on the Ansen may be the downfall for you and your bell crank may need modification. With my Lakewood I have at best a half inch clearance to the tunnel toward the rear of the housing. Then too, that Ansen appears to have a steeper taper. As far as my clutch combo, I've had an 11"- 143 tooth setup in mine forever because it was already there when acquired. It's worked fine but I'm not racing either. I do believe most versatile parts are in the 10-1/2" range these days. The MP book doesn't recommend 11" (full) for racing but provide no reasoning that I've found. I do have a 10-1/2" setup that will go in next time.
View attachment 1714929317