Hi everyone,

I ran into an issue with my 1938 Chevrolet Master while reinstalling the distributor. When tightening it down, the retaining bolt that holds the distributor to the engine block snapped.

I have a couple of technical questions regarding this setup and hope someone here can shed some light:

1. Is the spring original? On my setup, there was a spring mounted under the bolt head. Is this original from the factory, and is its purpose to keep tension on the distributor so it can be adjusted/rotated slightly when loosened without slipping completely?

2. Bolt Head: The broken bolt has a 3/4" head, which seems unusually large. Was this large head designed specifically to retain the spring properly?

3. Thread Size & Replacement: Does anyone know the exact thread size for this hold-down bolt? Is it 1/4"-20 UNC, or something else?

4. Temporary fix / Source: Is this bolt available from any specific vendors (seems  Filling Station and Chevs of the 40s do not have it.), or can I temporarily use a standard hardware bolt (e.g., standard 1/4"-20) without the spring until I find a correct replacement?

Any advice, part numbers, or exact thread specs would be greatly appreciated!

Thanks in advance