New owner of a Frankenstein K10

Hey everybody. I'm new to the forum, and sort of new to square bodies. I just purchased a late 70s 4wd to use as my play truck at my cabin in North Georgia. I'm looking forward to digging into, getting it running and looking a little better and making a few upgrades here and there. (I'll be going full-on late-70s/early-80s with the look--- roll bar with KC lights, mud flaps, big ol' 102" CB whip blowing in the wind...)

The truck was advertised as a 1979 K10 with a 400 SBC. It's not a show truck, by any means, but it seemed worth the price so I snatched it up. The seller had the old title, but I didn't really pay much attention to it since it was a Tennessee title and Georgia only requires a Bill of Sale anyway.

I trailered it from Tennessee to my company's shop about 45 minutes away from home, and I haven't messed with it since (gotta get rid of my '73 F100 before I bring another vehicle home). As I've been kind of sort of educating myself on 70s K10s over the last couple of weeks, I've run across a few things that don't make sense.

The truck definitely has a 400 SBC. I verified the casting #. It has a TH350, a 12-bolt rear and 6-lug wheels. As I understand it, all of those make sense for a K10. But... I happened to look at the title, and it says 1978 C10. So I'm thinking the guy gave me the wrong title. Again, I don't really care because I'm in Georgia and it's a pre-1985. Then I had a coworker send a pic of the VIN plate in the door jamb, and it indicates a 2wd C10 with a 305. So then I start to wonder what's going on.

Now I'm reading that all automatic K10s in 1978 had full-time 4wd, but this truck has manual hubs and a floor shifter. I would imagine converting from full-time to part-time 4wd with manual hubs would be a pretty common thing, though.

So what are the thoughts from all of y'all that know way more about square bodies than I do? Were all of these options available via special order (400 SBC, TH350, 12-bolt, 6-lug wheels, part-time 4wd)? That still wouldn't explain the VIN indicating a 2wd 305. Did full-time 4wd trucks still have a floor shifter to change between high and low? Could it be that somebody did a full body swap and put a C10 body on a K10 chassis? Or did somebody just start with a C10 with a 305 and go through all the trouble of converting to 4x4 and a 400 SBC? Did K10s have a different trans tunnel than C10s or something like that for me to check?

Obviously I know that none of you are going to know the definitive answers at to what is going on, I'm mostly just interesting in feedback on what the available options were back then and how common it is for people to do things like swap a 2wd to 4wd, swap full-time to part-time 4wd, etc. I know Chevrolets tended to be a whole lot easier to make changes to than the Fords that I'm used to messing with. Making those kinds of changes on an F-150 would cost more than just buying a different truck.

Anyway... thanks for the feedback. I'm sure I'll be on here over the next few months asking questions that any square-body owner should already know and getting made fun of by some of you, but that's fine. I can take it.

My guess would be its a k10 frame with a 400 swap. Original cab was rusted or damaged in some way and they put a c10 cab on it. Title is tied to the cab in most states. I know here in texas the title comes with the cab.

Welcome from Ohio. I have a Frankenstein truck myself. 79 chassis, 86 sheet metal, 77 motor. Plus parts from all years

Check the VIN number on the frame. That should tell you what the original truck was. Sounds like someone changed the cab.

Welcome from NC. Pull the rug & see if the hump in the floor has been welded in. 2wd & 4wd have different floors. It could also be that the truck was converted with a "K" frame. I would definitely check the VIN in the door jamb against the title VIN. Hope this info helps.

Strickland

Welcome from Far West Pa.

Welcome from the Texas Panhandle.

Welcome from Austria.

Thanks for the feedback and the welcome. I should be bringing the truck home in the next week or two, and then I'll do a little more digging for the VIN on the frame, check the hump to see if it looks like a different one has been welded in, etc. Sounds like some of y'all have the same suspicion that I have, though-- C10 body swap onto a K10 chassis.

What about the 4x4 system? Is swapping from full-time to part-time pretty common? It seems like a 70s full-time 4wd system would probably be prone to some problems.

^I don’t recall them being problematic at all on the few full time trucks we ran in the late 80s. And they were abused work trucks that were 10+ years old.
But the part time swap on those was and is very common to do.

Welcome, Dbryan 23. (weird for me to say "welcome", because I have been a member for literally 3 minutes. Just wanted to chime in on the 4wd (part time vs full time question). Since you have a lot of swapped out parts, you are really going to want to wait until you have your hands on the truck. Once you get it, check out the transfer case. If it is an NP203 and has been converted to manual hubs - then the transfer case also has been converted. My advice in that situation is "if it works, leave it be". The NP203 worked like a differential, transferring the power to the output shafts via chain. Everything newer is primarily a gear driven setup. Nothing wrong with the 203, but if your 4 wheel drive is working, that means someone has gone into the transfer case and installed an adapter (basically making it a "locked center diff" so to speak. You will be able to tell when you drive it. If the hubs are in the unlocked position, and you have to shift to 4 high to even get the truck to move, then the transfer case was not converted. You'll have to wait and see. You may get lucky and someone upgraded to an NP205. Nothing wrong with the 203, but 205's and up are a little tougher. (and don't have chain stretching problems.) Sounds like you have a good project on the way.

I had a similar situation back in the mid 90's but not quite the same as yours. I purchased a 76 K20 and the body was shot. I bought a 2WD complete truck that had a good body from a friend of mine. I swapped them, cut out the hump on the 4WD and bolted it into the 2WD cab. The State Police came out to my house and reissued a new VIN and riveted it to the drivers side door and then I went and got a new title so everything was legit. Anyway not sure that helps. Good luck. I'm not sure how common it is for people to do a complete body swap but I did it. That could be case with your truck but obviously I don't know. Hope that helps.

Welcome aboard from East Tennessee.