Building an IR-emitter and receiver on 3v3 Arduino


I'm quite a newbie in *duino, so maybe my question is silly, but it seems that Google doesn't know the answer. In my project i'm trying to equip an existing hardware with 2-way IR communication. The hardware's logic level is 3.3V. I'm using logic level converter based on 2 transistors to connect an 5V Arduino board using I2C bus. It works fine.

The question is: what difficulties will I face, if I use a 3.3v Arduino? Will it, for example, shorten the distance of IR signal? And does IRRemote library work correct on 8MHz board? AFAIK, the timer is very important for decoding IR - so maybe lowering the clock rate can cause some problems, can't it?

P.S. Excuse my poor english, please =)