How do you decide on what compatible NTFC fame size to use?

[johnharlin]

When converting frame size from Pal to NTFC, how do you decide on what compatible NTFC frame size to use?

For example, say you have a Pal video at 352 x 288 at 29.97 frames/sec, would you convert it to the closest NTFC frame size which would be 352 x 240 or could you choose any compatible NTFC format like.
352 x 480
704 x 480
720 x 480.

[edDV]

It is NTSC.

PAL should be 352x288 at 25fps not 29.97fps

352x288 usually has an aspect ratio of 4:3 with non-square pixels.

Equivalent for NTSC is 352x240. If you expand size 2x on the vertical and horizontal axies you get 704x480.

352x480 is usually used for interlaced video.