Grafting GMT 400/800 Dash into a Squarebody

[kcruzer]

I've recently seen pictures of 73-91 squarebodies with complete dashes from GMT 400/800s grafted in.

Has anyone down this and if so, can you share the process, pros and cons?

 

[Blue85]

Sorry I'm no help regarding your question, but why do you want to do this? Are you swapping that drivetrain and want to bring the controls/dash with it? Putting a ECM-based cluster on a carb truck could be quite a challenge.

 

[ZooMad75]

For what my two cents are worth, I wouldn't do it. Dimensions are completely different between trucks, both width and depth. The style alone makes them look out of place. If your main motive is to gain the cluster from a newer truck to go along with say an LS powertrain, you would be better off just getting a Dakota Digital or other aftermarket modern digital instrument cluster that fits in the existing dash.

If the modern cluster was a goal, 2003-2005 GMT800 clusters are known to be problematic. The motors that drive the needles hang up, stick or can wind all the way around. They were bad enough GM set up a special coverage to repair them well outside the factory warranty.

 

[kcruzer]

Sorry I'm no help regarding your question, but why do you want to do this? Are you swapping that drivetrain and want to bring the controls/dash with it? Putting a ECM-based cluster on a carb truck could be quite a challenge.

Fair question. My 73/89 Frankenstein is already running a 5.7 TBI drivetrain out of a 91 Suburban and an LS swap is something I'm considering. But even if I did not do the LS swap, the dash upgrade/update that I've seen looks really nice in a square body and building an analog instrument panel to fit in that space would not be difficult. I love the square bodies but the dash pads are hard to come by and the layout and function is both dated and not the most efficient.

 

[kcruzer]

For what my two cents are worth, I wouldn't do it. Dimensions are completely different between trucks, both width and depth. The style alone makes them look out of place. If your main motive is to gain the cluster from a newer truck to go along with say an LS powertrain, you would be better off just getting a Dakota Digital or other aftermarket modern digital instrument cluster that fits in the existing dash.

If the modern cluster was a goal, 2003-2005 GMT800 clusters are known to be problematic. The motors that drive the needles hang up, stick or can wind all the way around. They were bad enough GM set up a special coverage to repair them well outside the factory warranty.

Those are all things to consider and why I'm reaching out to find someone who has actually done it for to get their experience. The pictures that I've seen where the later model interiors have been grafted in, look really good. They fit and they really update the look - that's not to say that its easy or makes sense, but on the other hand, it could. I haven't taken the time to go and take measurements yet, but seeing that it's been done successfully gives me hope.

The squarebody aftermarket instrumental clusters are nice but are just instrument panel replacements. I've built a number of instrument clusters over the years to replace the panels in the various square bodies I've owned and that has been easy - but they did very little to change the overall look and function.

 

[ZooMad75]

I'm definitely not saying it can't be done. I've seen a few. My problem is the round peg in a square hole type of fitment. Looking at your top pic is what would drive me nuts. Stock round Saginaw steering column where the gmt400 column would have been. There isn't a clean way to overcome that look short of swapping in the later column which just adds to the fun.

Which brings another issue that would bother me, steering wheel shape. In the second pic they used the 400 column and the fugly airbag steering wheel. That wheel is just "blah" looking to me. That's my opinion, but those wheels were ugly when they were new. Yes you could still run a earlier 4 spoke non airbag wheel on the later column but then you get to see all of the later steering column between the spokes.

Ultimately it's your ride to do what you want. If you can overcome some of the issues that would drive me nuts, more power to you. I guess I'm just a fan of the original squarebody setup. Horrible ergonomics and all. I like the simplicity, the splash of color for the metal portion and it reminds me that I'm in a old more basic truck. I grew up in these style of trucks so there's some nostalgia there too.

 

[kcruzer]

I'm definitely not saying it can't be done. I've seen a few. My problem is the round peg in a square hole type of fitment. Looking at your top pic is what would drive me nuts. Stock round Saginaw steering column where the gmt400 column would have been. There isn't a clean way to overcome that look short of swapping in the later column which just adds to the fun.

Which brings another issue that would bother me, steering wheel shape. In the second pic they used the 400 column and the fugly airbag steering wheel. That wheel is just "blah" looking to me. That's my opinion, but those wheels were ugly when they were new. Yes you could still run a earlier 4 spoke non airbag wheel on the later column but then you get to see all of the later steering column between the spokes.

Ultimately it's your ride to do what you want. If you can overcome some of the issues that would drive me nuts, more power to you. I guess I'm just a fan of the original squarebody setup. Horrible ergonomics and all. I like the simplicity, the splash of color for the metal portion and it reminds me that I'm in a old more basic truck. I grew up in these style of trucks so there's some nostalgia there too.

I appreciate the feedback and agree it's not a perfect solution. Everyone has different tastes and ideas as to what looks good or doesn't, so I would expect there to be a plethora of opinions for and against it - and welcome all.

What I was really hoping for was there to be someone in the forums who has actually done one (or more) so I could better understand the scope, logistics and practicality of doing such an upgrade. If it's too big a hassle, too costly, doesn't work well, etc. - that would all play into a final decision

I was ready to build a custom fiberglass dash like the last picture but I happened across a bunch of pictures of the late model dash graft - and I've been drawn to the look and feel of that padded dash every since. Ultimately, I still may end up building a custom fiberglass dash to hold a large LCD android head unit, if my exploration into other options doesn't pan out. Either way, since I built custom gauge clusters for all my previous Blazers but retained the original dash, this last Blazer (I'm getting too old for the fun stuff) will not be stock.