The T-Zone still has a virtual, if you like, pancake core. So there is no true pin. There may be what looks like a pin that held that core in place. Most pancake cores had/have a different around .020". The only important part is the CG and that is responsible for most of its reaction. That said, You can use a drilling that will modify the differential and the dynamics:
http://wiki.bowlingchat.net/wiki/index.php?title=PBA_Plastic_Ball_Layout

The Slingshot may have had a smaller differential but it's a true dynamic core and the pin does represent the top of the core. So the dynamics can be manipulated via the pin placement.

Thanks for the information.
As for the polyester surface, is it ok to sand it if I want it to skid less and start up sooner?

Because of the nonporous nature of the polyester used on bowling balls,  surface changes make much less of a difference...

Thanks for the information.
As for the polyester surface, is it ok to sand it if I want it to skid less and start up sooner?

Polyester is more like urethane in that when you sand it, it hooks more, not just earlier. Polyester doesn't flip like resin when polished. It also doesn't burn up early in the midlane like resin does, and then flatten out in the backend. So while it still doesn't hook much, with too much tilt or rotation or too little ball speed, polyester can still hook enough to be problematic

If you have a problem with picking/chopping the 6 off the 10 or, for lefties, the 4 off the 7, then you've got to give it more room to hook or to throw it with either a flatter release or with more ball speed.

Also it can be drilled to be more rolly and even (like CG on the PAP, with a hole to take side weight). This will hook very early, but you will hardly ever chop anything. It will hook. I've tried this and do not like. I think I'd rather use simple negative side weight to reduce backend on pancake core polyester ball.