I just had an experience I would like to share with the group. I'm the guy who just did the 3.55 gear ratio conversion in my restored '36 Chevy pickup. One result of the conversion was a speedometer error of 17%.
In my youth in the 1960s I made a rat rod out of this pickup before restoring it in the 70s. When it was a rat rod I installed an S.S. White speedometer ratio corrector on the back of the speedometer head and now, 45 years later, I still have it.
Doing some research revealed that S.S. White's speedometer operation was bought by a Canadian company, Mr. Speedometer, decades ago. When I called Mr. Speedometer, the company owner Vic Collinson personally took my call. I told Vic about the ancient ratio corrector I still have and asked him if there was any chance he might have some replacement gears for it that would yield a 17% overdrive to correct for the gear change.
As you all well know from doing similar searches, the answer I expected was "No, we discarded all that stuff long ago, and in any case we don't sell parts, only complete units". The actual outcome was completely different. Vic told me he hadn't been into that inventory for about 20 years and that he would have to check some old catalogs and check what inventoy was left. A few hours later he called me to say that he had the 4 internal gears that would yield the 17% overdrive I wanted, took my credit card number and a few days later the parts arrived in Northern California from Calgary, Alberta Canada.
That exceptional customer service seems worth passing on to the Stovebolt forum.
The company name is Mr. Speedometer and their phone number is 800-661-1649.
The web site is
Mr Speedometer Apparently the speedo ratio correctors are not a huge part of their business since they specialize in new instrument sales.
