That's what I was thinking...crank windows, vinyl floors, but ordered with AC!
The RPO code for the trans is M20. I have seen other half tons with the New Venture 5 speed transmission, but none with the 4 speed. It seems like the 4 speed would have been mostly put in the 2500s and 3500s. Does GM have production numbers available for these trucks? I am curious how many folks ordered trucks like this.
That's how my truck is. Only options it doesn't have are the Silverado trim package, power windows & locks and the Gov-Lock rear end.
Your truck has a plethora of other options as well; Bright rear bumper, tow hooks, the deluxe two tone paint scheme, up level front grille (Quad headlights instead of two), tape deck, 4x4, that dump truck trans (lol), the bright mirrors and the alloy wheels.
The NV4500 didn't come into play until '91. On half tons, the 5LM60 was the manual+over drive option and then the heavy duty trans you have. I think what you've got is the SM465, that may have only been available in 3/4 or one ton trucks though. Need another member to clarify.