Low seat backs 2004 GT

You can most definitely install S197 (2005 or newer Mustang seats). Sounds like you must be a bit tall though so I'm not sure if it will help you out or not - I'm 5'11" so I can kinda relate to the issue you're having with the belt but honestlly it's never bothered me; 6'2" or 3" might be a different story. The seats themself though are lightyears better in every possible way than your current ones.

Here's a pic of mine, just did it a couple weeks ago. The short story is removed the S197 brackets and drilled holes in the seatpan to install the brackets from my old seats. Spliced the wires from the driver side bracket to the switch panel on the new seat; all power functions were retained.

Thanks SoCal2V. I'll be looking into some seats from the yard if I can find some lol. Stay cool H-

Anyone know about this company and these seats

Those look like Ebay seats, amiright? Personally I wouldn't do it, the quality and longevity probably isn't there. Seats like that would be good for a project like if you were building a sandrail. I Googled "KC Speed seats" and all I came up with was a bunch of links for a racetrack in Kansas City MO.