Default Just got a rooted/safestrap 4.3 note 3. How do I use a kitkat rom

I was lucky to get a refurbished note 3. It came with Android 4.3 so I rooted and installed safestrap. How do I use a kitkat custom rom? Is it as easy as just flashing it? I thought you couldn't flash a rom with a differ base?
Thanks so much!
OnePlus One = Good