going to install my oil pressure gauge on top of the oil filter housing-which is a 1/4 npt fitting. how to i figure out/convert that, so i can install a 90 degree a.n. fitting ,which runs -6,-8,-10 and so on. thanks

 

Use an NPT to AN adapter. Anyplace that sells AN fittings will have 'em. Summit, Jegs, whoever.

 

I'm not understanding the question exactly so I'll throw a few things out there, like Wanna said you need an adapter. You can not interchange AN and NPT fittings, they are vastly different, different pitch and sealing methods. If you're trying to figure out what size AN would equal a 1/4" to get an adapter, AN sizing is in sixteenths. So -8 equals 8/16ths, or 1/2, -12 equals 12/16ths, or 3/4.
-4 = 1/4
-6 = 3/8
-8 = 1/2
-10 = 5/8
-12 = 3/4
-16 = 1


hope this helps

 

thank you- you answered my question!! i learned something new today!