What drag radial?
I used MT ET Street R in 255/60-15 on my Valiant / 408 SB with good results. Best 60ft. with this tires 1.56 with some left due to wrong converter, i like them. For this season i bought a set of their Pro Bracket Radials in 28x9 because i wanted a bigger diameter - no results yet. These Radials are pretty good.
ThereĀ“s a bias ply version of the ET Street R better suited for stick cars.
Michael