Hello,
I just inherited this 1969 W200 (slant 6, of.course) crew cab and it's missing the carb. I'm having a difficult time finding the information needed to find one.
It has an unusual (to me, I'm a Chevy guy - don't hate!) manifold. Looks like a six legged spider, single barrel hole about 1-5/8" dia and the spread on the 2 mounting posts is approx 3" apart.
It has a small hole next to the mounting bolts at about 5 o'clock if you're looking from the front into the engine bay.

I tried to attach some pictures, but the files are too big and I'm too old to figure out how.

That intake is stock/standard; it's one of the things that made the Slant-6 work better than the competing Chev, Ford, and AMC sixes of that time. Does your truck have an automatic or a manual transmission? Automatic or manual choke (or choke missing altogether)? Do you have the air cleaner, or is that missing, too? This is a very good candidate. It'll bolt directly onto your intake, and linkage hookup will either be direct or fairly easily adapted. Air cleaner will either drop on or you'll want to get a pre-'70 passenger car type air cleaner to use with it. This carb is set up for automatic choke, so if you haven't got a good working automatic choke thermostat already bolted to the tower on the № 5 exhaust manifold runner, get a № 1231 Electric choke kit and you'll be all set on that front.

While you're at it, Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. See tune-up parts and technique suggestions in this post.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Wow, thanks for the info Slant Six Dan.
Manual transmission and choke.
I'll likely get that carb and will try to get some pictures posted soon. It's a cool truck, and appears to only have +-41,000 miles - was used on an airforce base, then stored in a hanger for a few decades.

Oh, I believe the air cleaner is on the back seat, but I didn't get a picture of it.

Air cleaner is probably an oil-bath type with a clamp band to attach it to the carburetor neck. Linked carb doesn't have provisions for that style of air cleaner attachment, so you'd want a '60-'69 passenger car air cleaner (place a parts-wanted ad on here and someone will come up with one; several different styles were used and any of them will work fine on your truck). Scoop up one of those linked electric choke kits because this carb won't work properly with the manual choke knob.

Sounds like a neat truck!

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.