Vintage AC aircraft spark plugs?

[snj-5]

Anyone have a link or reference for identifying used-on information
for vintage AC aircraft spark plugs? I did a Google search for
4708-AC-265 and AF-41-608-8221 but found no hits at all....

A neighbor & friend just came upon a quanity of "still in the tube"
NOS old aircraft AC spark plugs, and we'd like to learn what the
application is....

The tube says:

4708-AC-265
PLUG SPARK 18MM
.016 INCH
ELECTRODE GAP
QTY 1
UN EA
AF-41-608-8221
AC SPARK PLUG
FLINT MICH
MFG/CONTR.
5612019

Thanks for any guidance / assistance!

Bela P. Havasreti

[Wheels up]

Have you tried the plugguy?
http://plugguy.com/

[snj-5]

Thanks for that tip (it worked!). The Plug Guy says my friend has a cache
of NOS AC plugs that were original designed for full military power
settings on the Wright R-3350 while using 115/145 fuel.

Due to the lack of fuel availability, the only possible (?) current
application might be for Reno racers running the 3350.

Bela P. Havasreti