The original specification on the 261 PCV valve, for hose connections, is the AC CV609 (Weatherly Index 660).
The same valve is used on the next generation 230 engines (GM 6421235).
Make sure your FV410 has the same specifications as the CV609.
I wish I could, but those specs are made a secret, at least I found them nowhere.
The website doesn't even say if it is a fixed or a plunger unit, let alone any flow rates or curves.
https://www.fram.com/pcv-valve-fv410Meanwhile that Fram FV410 PCV valve arrived.
Turns out it is a fixed rate unit without a plunger - basically just a can with a tiny hole, and the hole is about 1.5 mm (0.078 inch).
If I had knew that, I could have saved 20 bucks and just put a washer with a tiny hole in the hose - well live and learn.
I mean really, how is this stuff rated anyway?
If you look up the applications for the FV410 on the Fram website,
they are all over the place for little 4 cylinders to 6 liter V8 engines.
And they all are happy with the same 1.5 mm hole in a little can?
