New owner of a Frankenstein K10

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

dbryan23

Junior Member
Joined
Mar 14, 2023
Posts
10
Reaction score
13
Location
Georgia
First Name
Donald
Truck Year
1978
Truck Model
K10
Engine Size
400 SBC
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.
 

animal

Super Moderator
Staff member
Super Moderator
Joined
Jul 30, 2010
Posts
5,467
Reaction score
3,623
Location
Georgia
First Name
Lee
Truck Year
1986
Truck Model
c10 silverado
Engine Size
350ish
:welcome:
 

Juggernaut

Full Access Member
Joined
Apr 11, 2021
Posts
204
Reaction score
222
Location
Illinois
First Name
Greg
Truck Year
78
Truck Model
K20
Engine Size
350
Check the VIN number on the frame. That should tell you what the original truck was. Sounds like someone changed the cab.
 

Strick

Full Access Member
Joined
Nov 25, 2020
Posts
1,239
Reaction score
2,995
Location
Dunn, NC
First Name
Harold
Truck Year
1979
Truck Model
C20 Crew
Engine Size
350
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
 

rusted nuts

Full Access Member
Joined
Mar 5, 2023
Posts
809
Reaction score
1,419
Location
Pa.
First Name
Jeffrey
Truck Year
1979
Truck Model
k20
Engine Size
4cly diesel
Welcome from Far West Pa.
 

WFO

Full Access Member
Joined
Jan 6, 2017
Posts
3,465
Reaction score
4,607
Location
Texas Panhandle
First Name
Dan
Truck Year
1986
Truck Model
K20
Engine Size
350
Welcome from the Texas Panhandle.
 

ali_c20

Full Access Member
Joined
Sep 20, 2016
Posts
1,071
Reaction score
1,487
Location
Austria
First Name
Alexander
Truck Year
1974, 1979
Truck Model
C20, K5
Engine Size
350, 350
Welcome from Austria.
 

dbryan23

Junior Member
Joined
Mar 14, 2023
Posts
10
Reaction score
13
Location
Georgia
First Name
Donald
Truck Year
1978
Truck Model
K10
Engine Size
400 SBC
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.
 
Last edited:

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,194
Reaction score
10,519
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
^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.
 

Mr Clean

Super Moderator
Staff member
Super Moderator
Joined
Aug 18, 2010
Posts
9,887
Reaction score
8,619
Location
North East Texas
First Name
Shawn
Truck Year
1982 & 1985
Truck Model
K10 Extra Cab w/ Proper SWB, & 85 K5 Blazer
Engine Size
454 BBC, & 383 Stroker
:welcome:
 

crustyrockers

Junior Member
Joined
Apr 15, 2023
Posts
2
Reaction score
12
Location
Little River, SC
First Name
Dave
Truck Year
1985
Truck Model
K10
Engine Size
305
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.
 

JACK34

Banned
Joined
Mar 18, 2023
Posts
124
Reaction score
149
Location
OTR TRUCKER
First Name
JACK
Truck Year
1978
Truck Model
C10
Engine Size
250
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.
 
Last edited:

Latest posts

Forum statistics

Threads
42,570
Posts
918,534
Members
34,110
Latest member
mundo
Top