[Sharps40]

Tire size question.

Both Ol John Lee and John Lee Jr have original wheels. They are approximatly 6.7x15 or 7x15.

Ol John Lee 1964 C10 (283 V8 - SM318 trans - 3.73 rear) is shod with new tires, P225-70R15 at about 26" tall with weight on. His speedo runs about 3 mph slow based on the Garman. These appear a bit too short but the right width.

John Lee Jr 1965 C10 (230 I6 - SM318 Trans - Assumed 3.73 rear) is shod with old/flat spot P235-75R15 at about 28" tall with weight on. I have not yet checked the speedo against the Garman. These appear to be a bit too tall and a bit too fat.

I plan to run the smaller Ol John Lee tires on John Lee Jr for now since they are new and have no flat spots. I want to upgrade to 6.7x15 or 7x15 steelies with moons later.

So, what is the most correct metric tire size to purchase for original size wheels. I want the right height for speedo calibration and to have the right narrow tire look as well.

Thanks in advance.