Tire Sizes

Posted by steve828 On 2011/10/23 8:44:24

I know there have been a lot of posts about tires, but I wanted to get some more opinions before I swap to radials. I am currently running a set of Commander 4-ply polyester cord tubeless bias ply H78-15 Load Range B (1770lbs @ 32psi) with a 28-inch diameter face on my 1954 Packard Clipper Super. They have a 3-inch wide whitewall and, according to my local tire dealer, the sidewall code indicates they are 15 years old. I am running the tire pressure at 24psi cold inflation pressure per my 1954 owner's manual.

I am concerned that, due to age, these tires may be prone to failure and I don't want to have a blowout at 65mph.

I would love to have a set of radial wide whites, but at around $1000 bucks for a new set, I am tempted to go narrow whitewall or black sidewall just to keep her rolling nicely.
I suspect the proper size radial may be 225/75R15 or 235/75R15 but I am having a hard time deciphering the tire size conversion charts.

Is there a definitive source for an easy-to-read conversion chart? Do you think I currently have a safety issue? Would you go black wall or should I save up my coins for the wide whites which do look nice on the car?

Thanks for all your help again!