need some info on centerlines

I wouldn't. Radials and bias ply tires load the rims in completely different ways. If it says bias ply only, that means they weren't designed for radials. Here's an article from SEMA that explains why...

https://www.sema.org/files/attachments/WTC-2011-05-Bias-vs-Radial-Tire-Wheel-Fitment.pdf

And here's the short version, quoted from the article linked above:
Summary :
• The tire industry makes radial and bias tires that can be mounted on the same rims.
• Not all wheels and rims were designed for radial tires
• Construction features of radial and bias tires make them bulge differently when deflected
• The radial’s localized bulge puts more stress on the rim flange than a bias tire does
• Rim fatigue and cracking can happen to any wheel from normal flexing, cyclic loading, and cornering
• Radial stressing of the rim can accelerate metal fatigue and rim failure that is uncommon with bias tires.
• Failures will usually occur where wheel materials change direction (e.g., flange to bead seat, bead seat to well, well or base to wheel center, etc.).
• Evidence of cracking may be visually obvious or it may be indicated by air leaking