@oleguer The CEA video modes you're referring to are set via tvservice, which doesn't work correctly on the Pi4 so those set of video modes are not available. The runcommand launch menu shows the resolutions that your TV reports it supports - that's what is offered for the video mode change.

You can set still a custom resolution via config.txt (see https://www.raspberrypi.org/documentation/configuration/hdmi-config.md) if you wish to use a video mode not reported by your TV.

@tonytoon I forgot to mention that the displays I have found are typically VGA, but many of them also have DVI ports. I found a cheap HDMI-to-DVI adapter which is the way to go. DVI cables are bulky, so this little adapter basically upgrades the display to HDMI.

Also, I un-shell them and discard the plastic bezel. This sometimes requires me to relocate adjustment buttons which has not been a problem. You end up with a screw-mountable steel bracket reinforced screen with the driver board/power intact, just not all of the branded plastic.

@edmaul69 Yes, tried the game mode. Thanks!

I figured it out. In the Retropie menu, I had to go into Audio options and change the audio output from 3.5mm Stereo to HDMI because I went from using a PC monitor with the 3.5mm out to full HDMI A/V on my TV. Now FBA and everything else plays smooth and sounds fine.