Timing issues converting from 23.976 fps to 29.97 fps

[Chaobunny12]

I'll keep this short and to the point- every time I convert my AMV (an .avi file compressed with Lagarith Lossless codec and at 23.976 fps progressive) to an mp4 or mpeg2 at NTSC 29.97 fps in zarx264gui or format factory, the timing is off. Not significantly, but just enough to throw off the lip synching in my video. Anyone know how I can fix this?

[Mister Hatt]

Stop changing the framerate when it is already synced.

[Chaobunny12]

It's for a convention submission, so it's going to be converted either way, and I'd rather do it myself.

And I got help elsewhere and solved the problem using TMPGEnc, so I'm good now. :3