I thought I'd gotten 2 bad pumps in a row from FLAPS for my 250. Then I happened to find a picture in the Chilton's book showing the fittings on top of the pump, instead of on the bottom like a V-8. Oops! I'd been installing it upside-down.
Don't know about the older 6's...

cm


If you can't fix it with a hammer and screwdriver, you need a bigger hammer.
1965 Chevy C10