Ford Model A - Suitable tappets

The original tappets on a Model A are not adjustable. You have to grind off some material to get the correct end play. I have replaced these tappets with adjustable versions.

On this picture you can see on the right hand side the original version, in the middle the single lock style and on the left the double lock style. I have decided to use the single lock style after an unsuccessfully trial with the double lock style version.

There are two reasons why I have chosen the single lock style. In this picture you see how far the tappet comes out when the valve is opened (see tappet on the right side). With this type it is easy to adjust the gap.
The nut of the version with double lock remains in the hole and it is not possible to adjust the tappets.