Check the shameless commerce division of
www.cartalk.com - click and clack's site.  I have the
gauge they sell; it's really well made and reads to
about 100 psi, expensive but worth it IMHO.  Plus, on the home
page you'll be able to recommend which engine "Ed"
should stick in his homemade plane - Should Ed fly
Subaru air?

I'm sure you listees will have some comments here!

Graham
90 GL auto CHC