Looking at a '76 K20 with a 400SBC tomorrow

[RecklessWOT]

Like the title says, looking at a '76 K20 Cheyenne longbed tomorrow afternoon. It's got a 400sbc, automatic (assuming th350?).

The thing is ugly as ****, it's 3 different colors (4 if you count surface rust, 5 is you count the spray painted markings on the driver door) and the crusty interior looks like it was parked with the windows down for a couple months. But besides all that ****, it's supposed to be solid, frame and body. I can handle an ugly, dirty, moldy truck, just gotta be roadworthy. If it is able to get an inspection sticker I'll most likely buy it, the price is low enough. Claims to only have 114k on it (could be 214, but hey who knows). Cosmetically it's completely ****** and I know that going into it, not worried about the way it looks or smells, I'm going to be restoring the 'burb over the next few months, I'll leave this one ugly just want a dependable truck to drag trailers around with and ****.

But I know very little about the pre-80 trucks, and have absolutely zero experience with the Chevy 400. Anyone got some pointers to throw my way about what to look for, besides the usual "buying any used truck" ****? I have owned 3 squares in the past, but they have all been square headlight trucks with 350s, and they've all been half tons. Just looking for specific **** about this truck I should keep an eye on.

Thanks guys, any info is appreciated!

 

[bucket]

Just the usual "buying a used truck" stuff applies. If original, it should be a th350/np203 combo.

 

[75gmck25]

As mentioned, stock setup should be the NP203 full time (AWD) transfer case and a TH350. The shifter will have H and H-Loc and L and L-Loc, with N in the middle. Many NP203s have been converted to part time (standard 4WD), and the tell-tale sign is usually the swap to lockout hubs on the axle. Stock NP203 has fixed front axle hubs that cannot be unlocked.

Look at the option decal in the glove compartment to find options, and look at the plate in the driver's side door frame to find out the GVW. If the GVW is listed as 8200 or 8400, it should also have the 14 bolt FF rear axle. HD cooling (or A/C) is a good option, along with dual battery, HD alternator, Gov-lock axle, and camper special or towing packages. Stock tire size may be 16.5", but its easy to find and switch to 16" 8 bolt wheels and tires.

The SBC400 has a mixed reputation. It has unique cooling problems because the cylinders are so close together, and this can cause problems. This article will give you a start on explaining the problem. https://www.enginelabs.com/news/steam-holes-the-cooling-mod-for-400-based-chevy-small-blocks/

Bruce