[cortcomp]

You need some basic pipe thread fittings. You can get it from the manifold directly, or from the carb fitting, or put a 3/8 T behind the carb and reduce the 5/16 line, etc, etc. Get sone pipe thread fittings and do what looks good to you, as long as you have an always on non-ported vac source.

Lowes, auto parts stores, etc have them....pipe thread is always tapered.