96K554 WELCH PLUG.  Leyland and Marshall Camshaft Welch Plug.

Fits at the rear of the engine block on  Harvest Gold Leyland Tractors and Marshall Tractors.

“Welch Plug” Wikipedia https://en.wikipedia.org/wiki/Core_plug.

According to Nevin Hubbard of the M.D. Hubbard Spring Company, the Welch plug was originally designed in the 1900s by the Welch brothers at the Welch Motor Car Company of Pontiac,Michigan. Hubbard claims that “at that time core holes in the engine blocks were fitted with pipe plugs. During one of these run-ins a pipe plug backed out. In order to get back on the road one of the brothers drove a quarter or half dollar into the hole. From this they developed the Welch plug, some with the help of my great grandfather Martin Hubbard. They then patented the plug and the M.D. Hubbard Spring Company became the sole manufacturer of the Welch plug for the life of the patent.

Fitted to:

• Leyland Harvest Gold Tractors 602, 604, 702, 704, 802, 804
• Marshall Tractors 602, 604, 702, 704, 802, 804, 904XL