i replaced my PCV set up with a catch can and SS line, and have since decided to change it around.

well now my problem is looking for a "Threaded Check Valve".

i want this to look nice under the hood and since most "PCV valves" will eventually leak under boost, i decided to go with a true check valve. most of these were designed for use with either Fuel lines or Brake booster reservoirs. most of the ones i've found are just barbed on both ends that will look like crap stuck in the middle of the nice SS line.

the best looking ones that will drop in are the Fuel check valves but i'm not sure if i can use those for air?

and i cant go back to the stock ones because my manifold and VC are tapped for NPT-AN adapters so nothing i can get at Napa / etc will fit.

Thanks in advance

Perhaps check the PCV for the 4G63, I know it threaded into their VC. It is metal, originally designed for a turbocharged motor. The other end may be just a push-on barb though. You could get crafty though and machine it/take a die to it and get somewhat of a pipe thread going on it.

As far as the fuel check valve, I know Earls and Aeromotive have ones with -AN fittings/threads on both ends. I would assume that it would work with air vs. liquid moving through it, but honestly the only way to test it is to buy one, and just blow on one end and see if it closes up :p

^^ I replaced the plastic PCV on my 420A with a 4G63 PCV and it is threaded, not sure of the size though since I just clamped hoses to both ends.

Also, you might wanna check at McMaster Carr (mcmaster.com), they have everything..