In the 1930's, Standard Hygrade had the largest assortment of aftermarket carburetor stuff.
Don't know what happened to Hygrade during WWII, but after the war, Standard Hygrade cut their coverage dramatically.
Carter, and the other carburetor manufacturers didn't really care for Hygrade, and I have several in-house documents where Hygrade parts had been compared to either Carter or Stromberg original parts. The reports were not overly complementary of the Hygrade parts.
Carter tools are, for the most part, readily available. Hygrade tools are not so readily available.
Jon.
