JMH,
See my discussion in your thread about oil in the vacuum lines, I think I may have found the Chevy part number.

Kent


1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix