1992 GMC 1500 to 90 Chevy 1500

I was wondering if the regular cab off of a 92 GMC 1500 (4WD) would swap onto my 1990 Chevy 1500 (2WD). I had the guy send me some pictures of the underside of the cab and the cab to frame mounts are different, so that’s why I ask. Thanks for any help!

The cabs are almost exactly the same, other than the hole on the passenger side of the firewall where the retainer block for the harness goes through, which can be overcome but take a close look first and you'll see what I mean.

Richard

Ok, is that a big job to swap it over?

1. Gut original cab of every bit of it's innards. wiring, dash, HVAC, etc.
2. remove fenders/splash shields, then cab.
3. Install new cab, and re-install fenders and innards.

Easy peezy! lol

Ok, that was kinda the plan originally anyway. I literally needed just the cab steel, as I made a botched repair and not the drivers side door won’t shut right. So I’d pretty much be doing that anyway right?

Take apart the one with the crummier interior first so you hopefully learn where the weak spots are on all the trim plastics. Take your time and really think them through because they will break if you're not careful, and even if you're careful they can break, just hopefully less. Plastics are getting harder and harder to find in good shape.

If it's a regular cab, with the cab gutted it's fairly easy to do with an engine hoist (extendable leg design is best, the fixed leg ones are easier to topple over) and some chains bolted on using the front cab mount bolt holes and the shoulder belt retainer bolt holes. An engine leveler can help, too.


If it's an extended cab you might wanna use a 2-post lift, instead. Much harder to balance that cab hanging in the air using an engine hoist, IMO. If you've got a shop area to work in that has an overhead chain hoist you could get creative with some straps but you'll need spreader bars to keep the straps from digging into the sides of the body and denting it.

Richard

Ok, well I kinda gutted some of the cab I was doing the repair on so I have a little “experience” with that. And I have 4 eye bolts into the trusses of my shop, and that supported the bed, so I’d sure hope it’ll do a cab. But all good things to consider. Do you happen to have any pictures of that retainer block/harness and the differences in location between the two?

I don't have a picture of the 90, but 88-90 are square with a single retainer screw, while 91-94 are rectangular with two retainer screws:



The harness that passes through there goes to your ECM, blower fan and A/C controls, etc. and it has a chunk of plastic stuck to it (I believe it may be glued, not 100% sure, never bothered trying to remove it) that screws to the firewall there as sort of a hard grommet.



Richard

Logan R said:

Ok, that was kinda the plan originally anyway. I literally needed just the cab steel, as I made a botched repair and not the drivers side door won’t shut right. So I’d pretty much be doing that anyway right?

Click to expand...

Joking aside, it's a pretty good sized undertaking. The first one you do normally doesn't go that fast. Tape and number everything you unplug etc. as not to leave or miss anything under the dash. Everything goes back in their proper clips/fasteners so there's no under dash rattles or squeaks. How fast it goes depends on how good you are at remembering how and in what order it came apart. I like to lay stuff out in order and not just throw it in a pile. Not difficult as it's all bolt together, there's just quite a bit of stuff involved.

Ok, so does that block need to be relocated with my different cab I’ll be putting on? And yea that’s the plan. Organization is key