Hi Joe,
1. I called Coker a few days ago about their 19" Excelsior Stahl Sport Radial Tires for Model A Fords.
2. Coker offers either their 500R19 "radial" tire, (SKU: 741761) @ $253.00; or their 550R19 "radial" tire, (SKU: 741771) @ $271.00.
3. Coker recommends using "only" their 500/600-TR-150 "radial" tubes, (SKU: 86431) @ $46.00 for both of these radial tires which comes with a 3-5/8" long center rubber stem, 1/2" diameter at the base. This particular size "radial" tube is not offered with their shorter 1-1/2" metal stem. Some say they have difficulty adding air with this long rubber stem .... (See further below "added" metal stem).
4. Summit & others have the above tires and tubes; however, sometimes, one has to type in the above listed Coker "SKU" numbers to find same, as opposed to entering only the tire or tube description.
4. Also, with Coker, for a material charge of $10.00 for each metal stem, plus a $5.00 "vulcanized" installation fee, they can provide this same recommended radial tube with metal stems for an additional $15.00; hence, with centered "vulcanized" metal stem each such tube would cost $46.00 + $15.00 = $61.00.
5. Have no idea if Summit or others offer these Coker recommended tubes with metal stems added.
Many outstanding Forum reports on overall Model A performance & safety for installing radial tires as opposed to bias tires.
I'll ask Coker a few more questions maybe tomorrow .... I just picked up my five (5) newly powder coated 19" wheels today.
Thanks Mr. Carl, Mr. LaVoy, & so many others for their wonderful reports on their Model A Radial tire improvements in handling etc.