Ron,
are you looking at the et street radial(DOT street legal) or radial slick ?like the hoosier.
i have used the et street radial for a number of years and been happy though they are sensitive to track prep.they are great on the street just don't go crazy in the wet ,though i have never had issues.
i used the 275/60R15,several friends have used the 295/65R15 all with good results
they are a BIG heavy tyre.for some reason they are too close to the dogleg on my Plymouth yet they fit fine on a mates 69 Roadrunner.yet i can fit the Hoosier 9.0x30R15 radial slick.go figure

Tex