[computerworks]

Mike - quick check in my data shows this:

Early 289 Cobra - 6.60 x 15 front, 6.70 x 15 rear Goodyear SS

289 Street cars - 7.35 x 15 cross-ply or 185 x 15 in radial
427 Street cars - 8.15 x 15 Goodyear Blue Dot

I am sure there were variations on this over time.