Dave,

In the small bore group people are using Hoosier Street TDs, Toyo ( the sticky ones) or Hoosier r6 now R7.

In the medium bore sedan group, which is made up of B-Sedan under 2.5L Trans Am (mostly BMW 2002 & Datsun 510s) they are almost all using either the Toyos or Hoosier R6/R7. Minimum weight for the 2002s is 1900lbs and 510s are 2000lbs (this is without driver) versus my car at 1670.

I've contemplated going with the Hoosier R7 in the same size but the bias ply tire is 4lbs lighter and and shorter. I lose out on the straights so every it helps. I haven't had a chance to email Hoosier and see if the radial R7 offers more grip (I think the bias ply is actually softer)