I have a old case crawler/dozer trying to find rebuilt water pump or company that rebuilds them. All the info I can find is a aluminum tag that has G-500 or C-500 then 241 on the left rear of the machine. the only thing I can find on the 4cylinder overhead valve engine is stamped MH, then looks like an A, then 260G then 63980. the water pump has 1921 on the housing and a casting number of H260K304 on the pulley. the pulley is attached to the shaft with an allen head bolt that holds the pulley on the shaft which wont come loose. the water pump housing has six holes where it attaches to the engine.