Have you adjusted the coverstock at all? Would be first thing I would try. I've taken my BBD from factory to close to 600 grit and back to around 1200. I've had sucess with each move, just on different lane conditions. Used it last night (polished to around 1000) on our weekly sport shot. Last night was the 2004 Masters condition. 39 feet I think. Backends were flying and the Big Block was the perfect ball of all my Hammers. Only left 1 ringing 10 all night. Other nights I may leave 10. If I keep hammering the pocket but can't carry the 10, even after trying different lines, I'll try another ball. Gotta justify hauling 4 balls (or more) to leagues every night! Mine is drilled fairly aggressive as well. Pin is 3 3/8 from PAP and cg is basically in center grip. Nothing fancy, but with the original Diesel core, ball still flares 4-6". I wouldn't recommend changing the drilling unless you are flaring over some holes. Try the surface changes first. Sometimes gotta change speeds to get this one to carry as well. And sometimes you just gotta go with something else! I know how you feel. There were times I was so frustrated with this ball it almost went out on E-Bay seveal times, but just gotta know when to NOT use it. Still a great ball in my opinion.
Hope you stick with it and find the best combo that works for you. Good luck.
Spike