A-65 Oil screen thread pitch?

Doe anybody know what the thread pitch for the oil screen is on a
Continental A-65? I have slightly boogered threads on the engine
threads and I want to run a set of dies through (I bought a tool with
the dies from McMaster Carr). It looks like 16 TPI is the closest.
Does that sound reasonable or does someone know for sure? I checked all
the ones that came with the tool by putting them over the threads on the
oil screen and let them drop in between the threads. Is that an
acceptable way to test for the right pitch or do I need to drop them
into the (female) threads in the rear accesory case, which would be damn
near impossible to see if they line up perfectly)? Any other ideas
(trying to avoid pulling the engine or rear case off)???

Scott
Corben Junior Ace with A-65