Thanks for publishing my letter [about stock wheels with tube-type tires, Oct. 1]. As far as safety is concerned, this is the situation: The typical rim section used in tube-type tire days [had] the rim riveted to the wheel center. A deep area of cross section [made] tire installation easy. The typical rim section for later tubeless tires [was] safer, but much harder to install or remove tires. Safety ridges ...help keep the tire in place when deflated [and there is] continuous weld construction.

Earlier steel wheels used with tube-style tires, first riveted construction, then later welded, did not have those extra ridges that usually keep a tire place on the rim. They performed poorly when pressure was lost. Tires got out of position with the loss of air pressure, resulting in loss of control and causing serious accidents. A sudden loss of pressure was called a blowout. When tubeless tires came into use, it was soon obvious that rims needed to be better. Heavier gauge metal and welded construction …. Plus, the fact that simple punctures generally caused much slower deflation, then made tubeless tires safer to use. Unless there is a major gash in a tubeless tire, it will not lose air instantly, as often happened with tube-type tires. Rim design has also improved to keep a deflated tire in position, although tires are now harder to install on rims. These changes came about in the 1950s. Now that we have one-piece alloy wheels, most younger people have never seen an assembled rim-and-wheel-center type wheel.
— Pete Harding, Gardnerville. N.Y.

Thanks for expanding on your original statement that tubeless tires are safer than tube-type designs. In commenting on their relative safety, I was thinking only of road damage to the tire, or tire-and-tube, itself, not the ensuing consequence of tire deflation on the rim. That was overly simplistic, as you point out.

You mention younger people’s unfamiliarity with older tire designs. This is not a recent phenomenon. In the late 1960s I had to show a young lad at a local service station how to dismount and mount tube-type tires for my 1953 Chevy pickup. He’d never seen them before.

I have read with great interest comments regarding slipping wheel covers when radial tires have been used. I have a 1951 Ford Crestliner that had this problem. I got five 1971 Lincoln Mark III wheels from the wrecking yard. They bolt up perfectly. They were designed for radial tires. I had them powder coated, mounted the tires and the full wheel covers fit perfectly. Several thousand miles later there have been no problems. Actually, there might be other Lincoln or Mercury wheels that will also work. For GM and others there might be similar swaps. More important is the safety aspect. Just making the original wheels work could be dangerous as they will crack and fail because they don’t flex as needed for radial tires.
— Walt Johnson, Portland Ore.

Thanks. I think you’re corroborating the wisdom of Mr. Harding’s advice.

In the late ’60s I bought a used 1966 Corvette coupe. It was a 327-cid/300-hp with a three-speed manual transmission on the floor and a 3.36 Posi rear. I have tried to find out how many Corvettes were made with three-speed manual transmissions in each year between 1963 and 1967. I have not been able to find any production numbers. When I tell people about this car, they don’t believe it came with a three-speed manual. Somebody should have the production numbers. I’m sorry I ever sold that car.
— Ron Caputo, Brooklyn, N.Y.

Although we seldom see them, three-speed manual, floor-shift transmissions were standard on Corvettes through 1969, according to the “Standard Catalog of American Cars 1946-1975.” For 1970 the four-speed was standard, while the Turbo Hydra-Matic was a no-cost option. As for production numbers, Chevrolet never made them widely available, but enthusiasts know their stuff. OCW contributor John Gunnell, a former editor (and moderator of this column) and author of the “Standard Catalog of Corvette 1953-2005,” came up with the data you are looking for. In 1966, of 27,720 Corvettes produced, 2,801 had Powerglide, 13,903 the close ratio four-speed manual, 10,838 the “regular” four-speed manual, and just 15 had a close-ratio heavy-duty four-speed. That leaves 164 with the “standard” three-speed manual box.

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