Yep, going to need to do a plug chop to verify. When i first put the pods on I went up 2 sizes to a320 and it ran great, but the smoke ring on the plug chop was very light colored. I jumped straight to the 340s and the bike actually still ran great, but the plugs looked better, so that is where she is staying. Like i said, on my bike, the pods required 4 sizes larger over a uni clamp on in the stock box with NO lid.. If you previously had a K&N clamp on then maybe the change wouldn't be as drastic, I dont know. I have never jetted a stock bike with shearers, so I cant answer the question accurately. If it runs good and doesnt' cut out at high speed, I would leave what you have in there and do a plug chop right away. May be perfect, may be lean, may be rich. Nobody can really answer.