the 1970 Sport Fury GT, a 2 door Mopar with the "GT" moniker.

 I also don't remember knowing that you could get a 440 6 pack Sport Fury in 1970

I've never heard of the S 23 model, I think that must refer to the first 4 digits of the VIN as the 2nd digit was an H or S which meant high or special trim line, and 23 was a 2 dr hard top, I think. Anyway, that's likely what the S 23 model refers to

https://www.overdrive.fi/forum/threads/vanhoja-valokuvia-ameriikan-raitilta.267070/page-1362#post-3584685