[Buzz]

Welcome to the club. I think 6X15 and 8X15 are relatively narrow by todays standards on a 427, but may look right on a 289 car or a narrow hip 427 street roadster. Tell us a little more about the Cobra. Is it a replica, and do you know the brand? 289 or 427 body style? The common 15" tire sizes for most 427 bodied cars are 275 60X15 rear and 245 60X15 on the front. Many go wider on the rears - up to 315 - if their body/chassis can accommodate the width. In some cases, certain cars are particularly suited to their own specific tire sizes that may differ from the above.