95-98 Dash To 88 Dash Swap.

[AK49BWL]

This sounds like a **** load of work, but I am still considering doing it.

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Anyways, the speedometer problem is actually an easy one to fix.

When I swapped the TH350 into my '95 Suburban, I was able to get the speedometer working by installing the 4l60e tailhousing/vss with a 40 tooth reluctor ring.

Despite differences with the sensors and the actual reluctor ring itself between these years, it still has 40 teeth, so in theory you should be able to bypass the buffer and hook the VSS directly to the cluster and it should work like factory.

Anyways, if I do the dash swap, I'm probably going to do it all with just junkyard parts.

Yeah, one small problem tho. The LS PCM needs that signal from the VSS to control the transmission shifting. The 95 ran its signal to the VSS buffer, which provided a 4kppm signal to the PCM. The LS PCMs expect the actual VSS, not the buffered signal. I'm not for certain, but MAYBE you could split the signal and send one to the PCM and the other to the cluster.

Or, use a 92-94 needle cluster and be able to use the 4kppm output from the PCM to run it. But if you want the Moonie gauges, then I'm quite interested to see how that's gonna work lol.

 

[Steven Petersen]

Yeah, one small problem tho. The LS PCM needs that signal from the VSS to control the transmission shifting. The 95 ran its signal to the VSS buffer, which provided a 4kppm signal to the PCM. The LS PCMs expect the actual VSS, not the buffered signal. I'm not for certain, but MAYBE you could split the signal and send one to the PCM and the other to the cluster.

Or, use a 92-94 needle cluster and be able to use the 4kppm output from the PCM to run it. But if you want the Moonie gauges, then I'm quite interested to see how that's gonna work lol.

He says he wants an 88-89 Suburban if they had made made one. So to stay authentic, he would need the rally gauges. Then he also needs to decide if he wants the 88 or 89 look specifically, as the early 88 gauges are different and the 88 bezel, radio and HVAC controls are all black.

 

[jjester6000]

Yeah, one small problem tho. The LS PCM needs that signal from the VSS to control the transmission shifting. The 95 ran its signal to the VSS buffer, which provided a 4kppm signal to the PCM. The LS PCMs expect the actual VSS, not the buffered signal. I'm not for certain, but MAYBE you could split the signal and send one to the PCM and the other to the cluster.

Or, use a 92-94 needle cluster and be able to use the 4kppm output from the PCM to run it. But if you want the Moonie gauges, then I'm quite interested to see how that's gonna work lol.

I like the needle cluster better anyways, I didn't know they are compatible.

 

[AK49BWL]

Yeah, 92-94 are like the 95+ in that they used an external VSS signal, be it from the buffer module or PCM. In fact, just about everything is compatible between the two.

 

[jjester6000]

Yeah, 92-94 are like the 95+ in that they used an external VSS signal, be it from the buffer module or PCM. In fact, just about everything is compatible between the two.

If that's really so, then I might actually go through with this swap.

 

[Pony93]

I'm in the midst of this exact project right now

Hope you're good with wiring, drilling out spot-welds, and have a lot of time.

You'll need:

The dash body: LMC sells them for $400+ shipping. You'll have to get most of the dash components from salvage yards.

The steering column AND intermediate shaft. You will need to drill the four holes for the column lower mounting into your truck's firewall. The good news is, the firewall itself doesn't need to be bent into shape, but you will need to cut a slot for the auto shifter linkage if you have an auto. The steering gearbox does NOT need to be altered.

The steering column SUPPORT. This is what the upper part of the column AND the dash attaches to. The 95+ column supports do not work, ask me how I know lol. This is where drilling out spot welds comes into play: there are four at the top of this bracket under the windshield, two above the brake pedal, and two between the upper and lower brake booster bolts.

Pic of my swapped-in column support for reference:

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I recommend you pull one from a 94 truck, as the brake pedal mounting is the same on them as the 95+. 88-93 I cannot guarantee are the same, as the brake switches are definitely different in those.

You'll also need the A-pillar trim for both sides, unless you modify your existing ones to fit the old dash.

Your existing door panels will work (as in, they won't mess up the dash) until you can find old ones, but fair warning you'll be looking a while for those. And unless you modify the door pin switches for the dome lights, I'd recommend leaving them unplugged because the older dash switches don't contact the newer door panels.

The rest is mainly wiring.

Pull a complete HVAC system harness from a late 93 to 94 truck. These should be 4-speed units - 88- early 93 were all 3-speed. Unless you're really going for that all-88 look in which case you'll have the blacked-out controller that only ran 3 speeds, and you'll need a wiring harness from an 88-90 to match that. Note on these, NO RECIRCULATION DOOR CONTROL until the 92+ controller. So you'll want to figure something out for that. You will need the mode door actuators too, the newer ones are NOT compatible with the old controls.

Oh and Idk how you'll go about wiring up the VSS for the old 88 Moonie cluster, as those have the VSS buffer built-in... Meaning the sensor on the transmission ran directly to the cluster. And if you have an automatic trans, that adds another set of linkages and such you'll have to swap in so the column shifter will work as designed.

It's a mess, lol. But it's doable

Also uh... If you have a 98-99, you're going to need to bypass the PassKey system, and the EVO steering from 97-99... And I really hope you don't have the electric-shift 4x4, because there really is no old version option for that.

You ever finish this swap? Any pictures. I'm interested in a similar swap

 

[AK49BWL]

You ever finish this swap? Any pictures. I'm interested in a similar swap

Indeed I did, it's nearly perfect. Check my project thread in my signature for pictures

 

[Pony93]

Indeed I did, it's nearly perfect. Check my project thread in my signature for pictures

Thanks!

 

[slow_c1500]

I have a 96 and I want to swap in a 92-94 dash. I’ve heard that almost all the dash wiring is compatible, you just have to re-pin the connectors. Is this true? And can I keep the 96 steering column and wheel?

 

[AK49BWL]

I have a 96 and I want to swap in a 92-94 dash. I’ve heard that almost all the dash wiring is compatible, you just have to re-pin the connectors. Is this true? And can I keep the 96 steering column and wheel?

You will NOT be able to keep the 95+ column with the 92-94 dash. In order for the dash to fit properly, the steering column bracket that's spot-welded to the firewall must be swapped. Doing so negates the ability to use the later columns. Repinning the gauge cluster is doable and the functions are mostly identical, save for the lack of airbag indicator, but you won't have an airbag anyway. The HVAC system has to be swapped if you're going to use the 92-94 controller; door motors, blower resistor pack, etc but you can keep your existing blower motor and the wiring harness is mostly standalone from the rest of the dash wiring. The radio needs no changes to the existing wiring, just the radio units themselves are different. Lights will have to be redone.