From memory, the arcade pcb has a slight border at the top and bottom of the screen if the vertical size pot isn't adjusted to make it fill the screen. If you don't adjust it then the game looks squashed.
The problem with the available resolution options on the arcade vga is that the game fills the screen before you adjust the v size pot so you have to cut off the top and bottom of the screen to make the game look right. If you leave it as just filling the screen then Ryu is as fat as Honda.
I don't really understand exactly how mame adds blank lines compared to the real pcb but if it looks right at 384 x 240 (after v size adjustment) then I'd be happy with that.
I can't believe that arcade vga cards don't have an accurate setting for SF2 of all games. I tried doing some custom resolutions with powerstrip but it doesn't seem to work well with the arcade vga card. There is only one resolution for EGA games with arcade vga cards too. EGA games with a vertical resolution of more than 384 lines (like Narc at 400) have the bottom of the image clipped.
I do have a few spare PCs and Radeon cards so I guess I should ditch the arcade VGA.
I use a multi-sync arcade monitor which auto switches, so I am not worried about going above 15khz while windows boots up. If my other Radeon cards don't put out 5v on pin 9 then it might be a bit more annoying to power my video amp but I'm sure I can figure that out. The v size and H size pots are on a remote board on my monitor which I keep upfront so making image size adjustments for each game is no issue. I need to do it when switching to EGA, VGA or 254 line CGA modes anyway.