K5 frame question.

[Cntymnty77]

Is there any difference between an 83 and a 91 k5 frame? I’d like to do a frame up restoration but also need a daily driver. I came across a 91 that I recovered tonight that had been stolen from a tow lot that we use at work and I can get dirt cheap. And by dirt cheap, I mean around $200-$300! It’s trashed and has been stolen twice. I had to figure out how to start it to drive it out of the field that we chased it into. The column had been busted and figured it out pretty quickly but when I drove it out, it felt very mushy. Once on the roll back I confirmed what I thought was going on. The trans support was hanging off the frame by a half inch.

Anyway, I can get it cheap and was thinking about getting it for parts, mainly the frame, doors, front fenders and other misc parts but didn’t know if I could put an 83 body on the 91 frame. I know it’s still a square but there are also slight differences in model years.

 

[swettysblazer]

Frames should be the same.... The year split was 80/81

 

[imiceman44]

Frames should be the same.... The year split was 80/81

This.
73-80
81-91

 

[Justin V]

To the OP's question, yes, 83 and 91 should interchange...

Just for sake of good info, the k5's had a floor change around 76-77, I think the k5 frames had a split there too, can anyone confirm that?

Thinking 73-76/77, then 76/77-80, then 81-91...

 

[nvrenuf]

I can verify tonight but, iirc, there's a part number change on the frame rails around '83. That said, I have no idea if there are actual differences.

 

[rampage]

I can verify tonight but, iirc, there's a part number change on the frame rails around '83. That said, I have no idea if there are actual differences.

Quad shock mounts in the front?

 

[nvrenuf]

Quad shock mounts in the front?

That was just an option so I doubt that's the difference. Realistically, they could be identical just something as simple as a manufacturer change. I tried to get my daughter to dig up my book but she couldn't find it, I'll double check this tonight.

 

[Cntymnty77]

That was just an option so I doubt that's the difference. Realistically, they could be identical just something as simple as a manufacturer change. I tried to get my daughter to dig up my book but she couldn't find it, I'll double check this tonight.

Thanks! It looked the same, from what I could tell, after we put it on the flat bed but I want to make sure before I buy it. I’d hate to get it home and tear it all down and find out it’s not.

 

[bmxbryant9]

Somewhat different comparison, my 75 body on an unk 80's frame required lift blocks on the front clip and no blocks at the rear of the frame/tub.

 

[nvrenuf]

Ok, sorry i sounded a false alarm.

You can see in the pic that there is a different part number for 83+ frames however the 1 rail that was serviceable separately covers 82+.

Also, the floor pan is the same 82+.

I’d bet the part number change is manufacturer related, not actual changes in the truck.

 

[Cntymnty77]

Ok, sorry i sounded a false alarm.

You can see in the pic that there is a different part number for 83+ frames however the 1 rail that was serviceable separately covers 82+.

Also, the floor pan is the same 82+.

I’d bet the part number change is manufacturer related, not actual changes in the truck.

View attachment 260902

View attachment 260903

Awesome! Thank you! I want that book too!

 

[nvrenuf]

Oh nooooo!

 

[imiceman44]

To the OP's question, yes, 83 and 91 should interchange...

Just for sake of good info, the k5's had a floor change around 76-77, I think the k5 frames had a split there too, can anyone confirm that?

Thinking 73-76/77, then 76/77-80, then 81-91...

Before I posted I was thinking of that, but the frame already had extra space that they compensate with the tall body mount.
So I think the frame might be the same.

 

[imiceman44]

Having cut up a few frames, I can tell you the first generation was a carryover from the pickup so the frame was same wiryh from the firewall to the rear bumper, the second generation the frame opened up wider under the cab, not sure if it was to accommodate the dip in the floor, which makes me think the frame year split might not be related to the frent end change.
The tub from 78-91 is the same so the frame might be the same

 

[tenderfoot]

I'm seriously considering putting a '77 tub & front clip on a '91 frame. I wouldn't mind a heads up on what will work and what won't. In my mind I'm thinking body mount brackets would be different but I don't know. It's a little ways off but I'll have them side by side in the shop for comparison, maybe a month out.

 

[imiceman44]

I'm seriously considering putting a '77 tub & front clip on a '91 frame. I wouldn't mind a heads up on what will work and what won't. In my mind I'm thinking body mount brackets would be different but I don't know. It's a little ways off but I'll have them side by side in the shop for comparison, maybe a month out.

It's been done unfortunately I scrapped it a few months ago but Colby Stephens put a 73 tub on a 83 frame, he had to build brakets to connect the 2 because as you assume they don't match.
Once they are side by side you will figure it out

 

[bmxbryant9]

The front clip will need brackets and the rear bench area body mounts will need custom mounts