@jimbotron235:
Why bother transcoding the AC-3 track at all? Keep the AC-3 track untouched and mux it to the final edit of your project.
The fps (frames per second) from the DVD—29.97fps—and the fps from the Blu Ray—23.976fps—are one in the same—both audio tracks will have the same duration.
If you didn’t change the speed of the AC-3 audio when you imported it to Premiere, then by all means, keep the audio you have in Premiere as a guide when you are editing–so long as your final edit is at the fps of 23.976.
When you export the video with that audio, mux the DVD’s AC-3 track to your edit. Compare the speed of both AAC and AC-3 tracks and see for yourself if they are sync’d properly.
It has nothing to do with frame rate. Besides, I de-interlaced and converted the DVD video to 23.976 before building the edit.
The AC3 track (and LD for that matter) can’t be added untouched. The director’s cut video has dozens of shots that are 1-2 frames shorter as compared to the theatrical cut. This results in numerous instances where the video and DVD/LD audio go out of sync. I can fix this here and there by inserting duplicate frames where appropriate but for shots where a judder would be noticeable, I have to trim the audio by the appropriate amount of time, and then export the edited audio track.