Never tried a K&N filter but just my standard caution for anyone considering Ram-Flo air filters (because there was a post on Ram-Flo filters somewhere which I now can't find).
I fitted one of these Ram-Flo filters to a '69 Ford Capri (2-barrel DD Weber) I had at the time largely because they had a reputation for better air flow and to make the engine sound a bit throaty.
Less than a year on and I was having the engine reconditioned. The engine builder said he'd seen it all before, blaming the air filter. The insides of the carb throats were filthy with dust. Apparently they really only filter out big rocks. This is anecdotal, of course, and for others YMMV, as they say.
I later went to an oiled foam Uni-Filter installed in the stock Capri filter housing and that seemed to work fine using the propriety 'sticky' oil. Apparently the rally guys swear by them.
There's lots of air filter options out there if you're prepared to either oil or wash these things.
Me? . . I gave up on the promises and associated maintenance and went back to the decades old and proven paper filters if only for their economical and fuss free nature.
On the Europa (Renault cross flow and 40DCOE's), I used the fairly short Warneford paper filters because there wasn't really much room to avoid interference with the fibreglass. I later cut away the intrusive bodywork.
The main problem with this installation was that rain would come through the vents and soak the filters - not much room for ram tubes, either. Finally, I made an air box and used a remote mounted paper filter more or less copying the TC which fixed the rain problem and shut up the racket from the carbs.
