Lookng for the diameter and thread size of the hole in the snout of a mid 80's
GM pump (The hole is used to pull the pulley on)

Thanks Mike D.

3/8"- 16tpi

OK so GM did not go metric on that hole when they changed the fittings, my bolt bin is getting to be a pain to manage (Big Jar ) may need to go with two Jars :)

Mike D.