KB-1 in Los Angeles

https://losangeles.craigslist.org/sgv/cto/d/1946-international-kb-1/6475441575.html

Nice truck, reasonable for whats bean done

Answers the question: "will an old odd-fire Buick V-6 fit in a K Series pickup?" Yes, it will! Set waay back...
The Buick odd-fire V-6 was used extensively in engine swaps once upon a time. Ummm...OK. Sure to shock a purist.

smoggy what's the poop on those Buick V-6 motors? I like this truck, color, condition,,,but is motor a piece of dooky?, or are they worth leaving in?

They SHAKE a little more because they are odd-fire. Later, when the crankshaft technology improved they (GM) were able to cut the crankshaft so that the 3.8/4.1 was even fire. Of course the early even-fire V-6s are lopey at idle, too.
Strange stuff...even the distributor cap is odd-fire. You HAVE TO line up number one on cap and number one on engine otherwise five cylinders are out of time?
If you devide 6 cylinders into 720 degrees of rotation you get 120 degrees on even fire and something like 105/135 degrees on the odd-fire. Just weird.
If you remember the 1970s and early 1980s just a bunch of old cars got the Buick V-6 as a transplant. MGs, Model As, you name it.
I guess I'd drive it until it proved to be a PITA.
I don't think it would scare me off. It's a compact powerplant so they shouldn't have hacked too much.
Last odd-fire I worked on was in an old Jeep. It took me a lot of work to explain why things had to be a certain way to the customer. They just have no idea. I think there's odd-fire Pertronix out there! Hilarious!

Thanks for the info, what would bolt in if this motor was yanked? Without major surgery

BRJ, I suspect the later Buick 3.8/4.1/3800 engines will fit.
I have a long history with these engines and actually saved all running gear/ electrical parts from a mid-1990s Firebird 3800 V-6 donor car. I wanted to put that drivetrain/electronics in a IHC.
Overall, I think the 3800 is wonderful. In the FWD applications (like Buick Park Avenue) I hear of crazy good mileage and power. Like 30s MPG while easily pulling a car full of people over the Grapevine. That kinda stuff. They usually pass smog check, too. In my world that engine has become legendary.
But I think you have the early odd-fire version. It, too, was installed because of the huge amount of power and economy it had from such a small package.
At any rate I'd be glad to trade you all my Firebird (RWD) V-6 donor stuff for whatever you'd offer in return if you'd like to update. This stuff is plug and play since it all from the same car. Missing...gas tank, fuel pump...
Something to consider.

Remembering this Firebird story as I go...I started to put all the Firebird stuff in a 1935 IHC C-1! It kinda fit! Suspension, everything.