My favorite tire on my Z was always the Goodyear Polyglas. The pic attached may be hard to see, but the tires are H60-15 and F70-15 Goodboots on the factory YH rims - these tires were on the car from '76 until a couple of years ago, when I finally sold them at the local auto flea market. Yes, they were a handful to drive, but a cooler tire never lived. Trips to the local 25 cent car wash always included a Brillo pad to clean the letters with -
Bias ply tires generally follow the ruts that are really on any road, interstates included. Ever notice how you can hydroplane easier in the right lane at speed on an interstate ? It's because of the slight depressions from trucks and heavy traffic in that lane, constantly, that funnel water in the lane, causing it to puddle and wedge under the tires. Radials resist it better, but bias ply builds are more sensitive to changes in the road surface. Couple that with manual steering, quick ratio, and these things were a challenge to drive - but I still love them (for the look !).
Driving my Pace Car home after purchase, some 125 miles in several July thunderstorms, was downright horrendous after so many years of radial tire equipped company vehicles (at high speeds). Car was all over the road, darting everywhere, hydroplaning, and drifting from side to side. First purchase after I got it home was a set of B.F. Goodrich Radial T/A's, which dramatically cured the ills noted on the ride home. I resolved never to run bias plies on the street, but as a show tire Goodyears still have the charisma.
Shame that Goodyear can't build a radial that looks like a Polyglas GT or Wide Tread GT of old -
Regards,
Steve