Dash swap 92 to 88.. yes you read that right

[CleeJay92]

I like the look of the older dash from an 87-88. I am hoping that someone knows if you can swap an older dash into a newer cab with out much difficulty. I'm working on a 92 project. I think the cabs are identical, but will there be a need for a different wiring harness or mounting brakets?

 

[adsm08]

It can be done. I have a 91 dash harness running my 87 dash, which is effectively the swap you want to do. Mounting is identical.

The wiring is a real PITA, and I wish I had taken better, or even any, notes when I built that harness, because the pinouts on the clusters are not the same., and the pins have to be moved around the plugs at the cluster. Fuse block mounts in directly, radio plugs are the same. Wiper and turn signal plugs are different, will require some modifications.

 

[CleeJay92]

It can be done. I have a 91 dash harness running my 87 dash, which is effectively the swap you want to do. Mounting is identical.

The wiring is a real PITA, and I wish I had taken better, or even any, notes when I built that harness, because the pinouts on the clusters are not the same., and the pins have to be moved around the plugs at the cluster. Fuse block mounts in directly, radio plugs are the same. Wiper and turn signal plugs are different, will require some modifications.

Sweet. So the air ducting and the fit is the same? That faux wood grain and the cluster is just way more appealing to me than any new replacement or the actual cluster from the 92. I should've looked for an 87-88. But when the truck was only 700 bucks to begin with, I took it on.

 

[CleeJay92]

Also, I have the whole cab from the 88.. would it be easier to wire the harness from the 88 spliced into the existing harness in my 92? I'm an extra noob btw.

 

[adsm08]

Also, I have the whole cab from the 88.. would it be easier to wire the harness from the 88 spliced into the existing harness in my 92? I'm an extra noob btw.

There are multiple ways to approach this issue.

Some people use a complete harness set matched to the dash. Some make an adapter to go between the two mismatched harnesses. I seem to be the only one interested in converting the newer harness to plug into the older dash.

 

[Shran]

"without much difficulty"... I just did this, I put a '92 dash into one of my '88s as part of a 4.0 swap. Here's what I ran into

- the big cannon plug in '92 needs the correct size hole in the firewall (not there on '88)
- first gen steering column does not attach well to the second gen pedal bracket nor does it look right with a second gen dash
- second gen column does not bolt onto the firewall, the hole is too small, so you'll need to modify your '88 firewall. I opted to cut a whole section out of a newer cab and rivet it in place
- second gen pedal assembly (needed for second gen column and dash) does not fit the first gen firewall very well, needed extra reinforcement and some things cut off
- upper dash attachment screw locations are different - I cut these off a newer cab and welded them onto mine and had to bend some of them to fit
- lower dash attachment bolts - driver's side one is fine, passenger side one will need a tab added to the '88 pillar (doesn't exist on 1st gens)
- clutch slave cylinder push rod (if you have a manual) will be too short no matter what with second gen pedals. I had to make mine over an inch longer and adjustable
- HVAC plenums are similar, fortunately enough so that you use original under the hood and the '92 parts in the cab - the defrost section is different so the first gen HVAC plenum won't work
- Cab wiring - use whatever you have from the '92, the plugs are different, it's routed differently, etc
- additionally, using the '88 fuel level sender, your new '92 cluster will not read your fuel level correctly, so you'll need to modify your sending unit to fix that
- If you use the '92 dash harness, you will also be using the '92 headlight harness, which requires different plugs soldered on for your headlights

If you got through all that, you can probably guess by now that it's a pretty big project. I had roughly a solid month into mine between researching stuff, tracking down parts, etc

If you're doing this as part of a 4.0 swap... go for it... if you are doing it simply for appearance, I really, really would stress that it is a huge project.

 

[adsm08]

Cannon plug fits just fine on my 87,

 

[Shran]

Here's a couple pics of the firewall... you can see where the column goes through on the second gen (big hole, left metal piece) and the same hole on the first gen is much smaller/bolts in wrong places.

I was a little premature regarding the cannon plug, it fits, but doesn't lock into the firewall. I sectioned that part out of a newer cab and welded it in place so that the dash part of the plug clips in place. Not 100% necessary but it's helpful.

Interior view after the firewall was modified for the second gen column