"New" 1981 GMC

[Axle]

Picked up a new square on the weekend, a barn find 1981 GMC 1500. Dash trim says High Sierra but that is questionable, as with every truck I come across, the SPID is missing. Hopefully I'll get to a dealer sooner rather than later to see if I can still get a list of RPO codes for it. (anybody here work for a dealer willing to run the vin? Canada truck if it makes a difference to what info is available on either side of the border)

Previous owner (GM Tech, 2nd owner, got it in 1983) added cruise control, and a/c from an '84/'85 truck at some point in its earlier life. Wheels from some other timeframe. Its rolled the odo over a couple times. 305 dualjet th350c and 12 bolt rear axle. Sheet metal is in great shape, as the only winters it has seen was the first few years of its life.

It has been painted sometime in the 90's and debadged. Interior needs a bunch/a lot of TLC and all the hoses need replacing. Thing still runs good, and even with the massive vacuum leaks it was well behaved and starts up quickly with zero smoke. Sips the gasoline compared to my '83, so plans for now are to run it as is until my right foot gets the itch. =-)

Interior smells like a barn... becuase it was housed in a barn for at least 10 years. For someone who has never named a vehicle (other than the standard curse words thrown at them when warranted), it has coined itself 'the farm truck', fitting for where it spent its life.

Some questions that you guys more than likely can answer;
-What year (year range) is the A/C from? Did that compressor get introduced in '84 or '85? I'm inclined to suspect 1985 since the instrumet bezel is an '85 if the a/c specific stuff came from the same donor truck.

-What is that contraption in the air filter housing? Some sort of backfire supressor? For all the cars and trucks I've looked at in the yards, I have never, ever, seen an inner metal mesh filter. Does it require periodic cleaning/spray down with carb cleaner? Whatever it is, it seems like it is crimped to the air cleaner housing, which doesn't lend itself to easy maintanence.

On to the pics, barn pic later as those are on my now self destructed other computer.

Alex.