Changing Projects Frame Rate

Hi there,
I'm a pretty new user of motion and so far I don't know whether I'm pleased with it or dissapointed with it.
So I'm doing a project in avid and I'm doing an end animation in motion. I was told recently that motion graphics work better if you set the projects frame rate to 24fps instead of 29.97. I wanted to try this so my project is currently at 24fps.
When I export it and bring it into avid, it has serious field flicker (which I know is a result of turning 29.97 footage into 24.) but it's also a lot faster. In the comp it seems to run fine and sync to the voice over audio but when I bring it back into the Avid its quicker.
I was wondering if there is a way of changing a projects frame rate? I already looked at some functions but it doesn't seem like I'm able to alter a projects frame rate after I've started it.....
any suggestions?
thanks a lot
kyle.

Make you project at 29.97 and you should be fine.

hey mark,
thanks but I don't think that will work. Like I said, when I look at "project properties", the frame rate is displayed but I cannot change it. I already created the entire project at 24fps, this is also a pretty complex little project in terms of keyframes. So when I create a new project at 29.97 and then copy over everything to that, its still short and if I lengthen it, the keyframes will not lengthen according to the clips length. They just stay the same.
Hope that made sense.
thanks.
kyle.

I'm talking about the frame rate of a clip, not the project.