Here's a story about a friend of mine who tried K&Ns on his dual Stromberg set-up. I SWEAR I am not making this up...
...it all started just outside of New Dehli. My friend lost his camel to dehydration before entering the city. Now, mind you, the camel was not dehydrated, but, rather, he was. And in his current stupor, he tied his camel to what he thought was a hitching post. It was really a swami's outstretched arm. The swami quickly left with his camel, leaving him without a vehicle.
Upon stumbling into the city, he found himself upon a used car dealership. And surprise, it was run and owned by another swami. He was talked into purchasing a low-mileage Range Rover, circa 1981. Now the vehicle looked to be in good shape, but like any used Rover, caveat emptor. Especially if a swami is selling it to you. They'll con you out of your last wicker basket. And people thought the gypsies were a scourge.
So, as the story goes, he decides to drive his newly acquired rig to Thailand (Siam for you well-read Roverphiles) where he can then have it cargoed over to Australia. The drive, however, is quite longer than the grocery-store variety distance us American's are known for. He decides he needs to make a few performance modifications to improve his miserly engine output, as well as the fuel economy.
First on his list are new K&N filters (surprise). He unfortunately had to wait three weeks for a set to be shipped over from Australia; this was necessitated by another ill-fated purchase from the aforementioned swami (not the one who stole his camel, the one who sold him the Rover). See, as it turned out, the "Performance K&N" filter he purchased was actually two dirty socks and two plastic Dixie cups.
Well, after that dilemma passed, the authentic K&N filters arrived and he installed them the next morning. Expecting an instant increase in performance and drivability right out of the box, he fired the Rover up. However, as we now know, the air-fuel mixture at the carbs were perturbed due to the vast air-flow capacity of the new filters. Instantly, the fuel mixture ran lean and the muffler erupted with an outrageous backfire that brought half a block of peasant shoppers to the ground fearing Pakastani insurgents had made it very clear past the border.
Amidst all the shock and embarassment, the relief of a simple backfire instead of gunfire was short-lived. See, at the time a young woman of marrying age (e.g. 12 years old) was in the proximity of the muffler as the volatile gasses combusted. She was rendered blind by the concussion, or flying carbon debris, or both. Faced with social-political repercussions, he immediately knew what he had to do. He had to marry this poor, cripled woman.
As with any modern custom, he immediately burgled three cattle from a village two towns over in order to present the woman's father with an acceptable dowry. Upon delivering these cattle to the woman's father, he realized the father was actually the shifty-swami who sold him the fated Rover and the K&N sock kit. He also recognized his camle on the other side of the swami's fence. Simple logic left him with the conclusion that this was also the swami that stole his camel.
In a rage, he began to swear in ancient Gaelic which sent the cattle into a stampede heading for the blinded woman. Well, she jumped right out of the way, then picked up a nearby rock and threw it at the fleeing cattle. Obviously, she was not blinded at all by the backfire and the whole injury was a ruse. It turns out her disfigurement was previously attributed to an acid-attack from a vengeful neighbor over 2 chickens and a half-dozen eggs some years ago.
Realizing these things, he grabbed his camel and high-tailed it out of there, leaving his Range Rover to sit and rust on the Swami's property. It's purported the land downwind/stream from the decomposing Rover was rendered barren for any agricultural venture. Years after building a school on that property, it still is unclear if a particular regional ailment in the children were due to the Rover, or possibly school milk.
Finally, I don't know what the hell my friend was doing in India on a camel. Moron. But there is a lesson to be learned. A camel is better than a K&N. Put that in your pipe and smoke it.