Inlet size for air filter

Okay, I have a simple question. I have a K&N filter with a 3" diameter inlet installed on a 2 1/2" diameter AEM short-ram intake. I sealed it with the rubber hose clamp that came with the filter. Reason is someone stole my filter (don't ask) and my friend gave me his extra one. It seems pretty sealed and so far so good. My question is will this cause any problems in the longrun? Thanks.

if it is on there so that it doesn't fall off, it will be fine....

yeah as long as you sealed it tightly and no dust or dirt can be sucked in around the filter then you will be fine.