IH began with tachs in 1955. Any four cylinder IH engine from that date until 1958 that has the tach drive hole and 2-screw cover can use any of the three tach drives. IH Gas or Diesel use the same drive. They are interchangeable. Later models of the Cub and 140 also use the same drive.
You need a gas tach. The Diesels rotate backwards. You want a 0-2400 IH tach with the "0" on the left hand side. They will all work but the road speed numbers will be slightly off. The 540 RPM line will vary also.
Tachs are being reproduced and they are a quality item. You can find them new on eBay between $60 and $130.
I don't believe there is a source for new tach drives. Used drives (usually as part of the distributer drive) can be had on eBay for around $50-$100. You take your chances on a used drive. The gear is plastic and may be stripped. eBay buyer protection plan will refund your cost if the drive is no good.
You need a gas tach. The Diesels rotate backwards. You want a 0-2400 IH tach with the "0" on the left hand side. They will all work but the road speed numbers will be slightly off. The 540 RPM line will vary also.
Tachs are being reproduced and they are a quality item. You can find them new on eBay between $60 and $130.
I don't believe there is a source for new tach drives. Used drives (usually as part of the distributer drive) can be had on eBay for around $50-$100. You take your chances on a used drive. The gear is plastic and may be stripped. eBay buyer protection plan will refund your cost if the drive is no good.