[Ant]

Unless you can afford an alloy FE 427, SB is the way to fly for track use generally depending on track design, as iron BB's don't enhance the handling at all, there are some that claim with 50/50 weight distribution it doesn't matter - well bulls**t.
If you want tire ripping grunt for the road, the BB's definitely do it.

Cheers Ant (BB fan but don't like the broken axles and poor handling)