Being that I posted this in the 73-87 blazer jimmy suburban section that should narrow it down I would think? Being that blazer and jimmys dont have back doors that would also narrow it to just suburbans, at least in my mind it did.
Regardless its an 89 GMC R3500 Crew Cab with a turbo 400 transmission and a 454 engine.
And before anyone says 89's dont belong in this section heres a picture.
Thanks!