I have one of these Perry coolant filters in my daily truck and 235 for about 3 years now.
Never heard or seen anything about them either, until your post.
This filter works great and it showed how much sediment floats around inside a used engine.
Maybe less effective on newly rebuild engines.
I still have the original installation instructions.
The filter came supplied with two fittings. and was supposed to be mounted on the driver side inner fender.
One fitting connects a 5/8 hose from the drain outlet on the driver side rear of the block to the bottom of the filter.
The top of the filter connects to a tee at the water pump/heater hose inlet.
The filters small outlet orifice regulates and slows the flow through the filter.
I installed it because there was a lot of build up, especially in the rear of the block, which is typical for most used 235s.
Even after serious flushing there was still fine sediment suspended in the coolant.
At the time I switched to a waterless coolant, which doesn't react with the cast iron block and never creates build-up again.
A filter would get rid of every small particle once and for all, so I installed this NOS filter.
I just re-used the original filter element and flushed it clean every few thousand of miles.
Could have rolled up high-temp-foam instead, I guess.
Now after all these miles, the filter has done it's job and I will remove it next weekend actually.
Never thought I hear somebody else mention this filter.
