Hello and welcome to the forums-
Does this sound right?
Yep.
There are several ways to find the information you need to adjust it, but I prefer getting the information from
FitCD. And it's free. Just a quick check to convert a 16:9 DVD to 4:3 DVD gave me this (for NTSC):
LanczosResize(720,368,8,0,704,480)
AddBorders(0,56,0,56)