IIRC in 93 or 94 they changed the plug on the back of the radios. Metra makes the necessary wiring adapters to use a newer factory radio in the older trucks w/o doing the old cut paste thing. Mid 02 is when GM switched the S10 to double din from your 1.5 din.
Can't for any reason figure out why they used the stupid Din crap. Just say 2, 3 , or 4" radio. They're all 7" wide, DUH.
Well then call them 50, 75, and 100. DIN stands for Deutsches Institut für Normung which the Germans starting using to standardize the radio's in Audi's, BMW's, Mercedes, VW's in the 80's. When GM already had a 3" radio.
If I was driving a German car I would expect them to use German standards. As an American I demand the right to know what size my red, white, and blue radio is. Even if it is made in Mexico from Chinese parts.
I'm well aware of what they're called and can live with it. My objection was to the whole auto industry adopting a standard concocted for VW and Audi. I'd be willing to bet the reps from GM and Chrysler objected when ISO decided that the worldwide auto industry would adapt a standard that wasn't really meant for 3" radios which GM and Chrysler were already installing. Making the millions of folks with 1-1/2 din radios the ugly stepchild of the audio world.
Why the aftermarket was so quick to act like the 1.5 din never existed is also confusing. You simply can not buy one today. With a few rare and expensive exceptions like RetroSound starting at $320.