What to use to plug AIR fittings for LT1 Pacesetter LTs

What type of plug, size and thread please?

Not familiar with the pacesetters, but I used 2 M22 (22 millimeter) oil plugs from autozone on my Macs.. They are a close fit for the oddball 7/8 thread size used for the original inserts into the stock manifolds and worked for me. May want to grab a couple and try them out. Can always bring them back if they don't fit...

This is what I got for my 94. http://www.cgenterprises.com/drain_plugs_metric.htm

Its #1016.

22mm-1.5

i went to a hardware store, and kept buyin em til they worked, and a 5/8" nut worked