Humm I got a sweet as high zen pipe that I modded, takes me to 57mph at 12x44 with great pull I would sell you. I'm on the search for a 65 mph pipe... Email me if interested and I will send you some pics.
I really don't think a bk100 would do well on your planned setup, but you never know! I would go to 11x40 (are you sure it's a 40? I thought the rears were all 44) and get some blue clutch springs! You should be thrilled with that setup!