The Walker Air-Sep on the Perkins is definitely the way to go if you have the bucks, I am somewhat more "thrifty" and mechanically inclined, so I went with a K&N filter for about $30.00 - I used one of the Universal fit sort, with a 2 1/4 inch opening and hose clamp ( I think, need to measure that before you buy) and plastic ends to have less of a corrosion
problem. Took off the old "air cleaner", clamped the K&N to the intake stub, ran the hose from the valve cover to the bottle, and I was done...$30 for filter, 3 ft of hose at $1.19 per foot, scrap oil
bottle and foam filter material, and 10 minutes.
I have seen this done where a fitting was installed to the end of the filter with epoxy
and the breather tube run into the filter through that fitting. I might try this if I could be sure of the fitting and such not coming loose. I am not a fan of loose parts
trying to find a way through the engine when they loosen over time, which they will.
I have also seen this on this forum, I think, where someone made up a piece of 2 1/4 exhaust
pipe with a brazed piece of pipe on the side that was 5/8" o.d. for the hose from the breather and clamped that to the intake flange and the filter to the other end of the pipe. This is a much neater solution, but does require a little cutting and welding...probably a muffler
shop could make this up for you. A paint
job would help with corrosion
. I'll do this when I have time.
Just FYI....until around 1965 or so, just about every automobile in the United States had valve cover breathers that vented directly to the atmosphere. a motor
in good shape doesn't pass much gas or vapor out a valve cover vent. It does vent some, hence EPA regulations
stopped the practice.
I'll send pictures next time I am on the boat.