Originally Posted by MRF582
Also, this last statement confuses me. How do you connect a -8AN or -10AN connector to the same fitting?
Because both a -8 and a -10 fitting can use the same threads on the other side of the fittings. They could both be a 1/2" NPT for example, and one could be a -8, and the other fitting a -10. So either you pick what size you want when you order, or both size NPT to AN fittings are provided with the kit.
I'm not questioning the design of the catch can at all. It is a good design and works to catch the junk coming out of the crankcase.
The bigger question to me at least, is why wouldn't you want to pull vacuum through the catch can, providing a positive flow to evacuate the blowby emissions?