factory plug confusion?

[ForOffRoadDriving]

so yesterday my dad and i were going to swap stereos between the two trucks he owns, a 1989 std cab long bed with an aftermarket jensen cd player (i told him to throw it out and buy an inexpesive pioneer but hes not like that), and a 1993 extended cab with the factory dolby cassette player (still works fine and even plays cassettes but doesnt know what to do with a cd). to the best of my knowledge all rangers from 83-94 used the same radio connector, the standard 2 plugs (8 pins on each) and antenna but when i unplugged his i found this

heres the build sticker on the door jamb

we ended up going to the store and picking up the right adapter for "94 and newer selcet vehicles", but my question is does his 93 have a premium sound of some sort or did the standard connector change at some point?

 

[Ranger SVO]

Your truck has an amplifier (mine also had an amp, it had the factory CD player). The plug you need will be the 70-5511 (metra part #). Remember to hook up the remote wire on the plug so that the factory amp turns on.

 

[farmer]

yeah i made the mistake of cutting that plug off then realized i had to run new wires now.... oh well

 

[ForOffRoadDriving]

well i got the cd player installed in his truck a couple days ago, it sounded great at low volume but once i turned it up everything sounded like crap! so i pulled the door panels off and his factory speakers were missing the rubber surrounds and the paper center cones were the only things producing clear sound (but only at low volume). i decided to give him the lightning audio speakers that i had in my ranger before i installed and amplified the new mtx ones. its perfect for him cause he doesnt know any better (sound system wise) but i couldnt live with it, hell i cant hardly even read the numbers on the display but he only listens to one station so i guess he doesnt need to read it either.