91 GMC C1500

[s98gmc]

Hey all,

I bought my truck about 18 months ago. It was an unfinished project. I don't know the full history and didn't buy it from the person who started the build. Here's what I do know:

It's a 91 cab on a replacement frame. A 98 Chevy was used for parts, so it has a 98 5.7l and a full interior swap. It also has a T56 6 speed, front and rear sway bars with polyurethane bushings, Eaton posi, Belltech suspension, and some details I've probably forgotten. Despite being in Maine, there's no rust. It's garaged during the winter months.

This unfinished project looked rough when I bought it but was mechanically sound. It's been repainted and I finished the interior swap. My uncle and I did the prep work and a local guy sprayed it near the end of summer in 2017. The dash, door panels, a pillar trim and headliner were installed but the rest was missing. It has leather buckets from a Chrysler LHS. I bought some pieces from LMC truck and sourced the rest from a local junk yard. The electric mirror wiring was missing, the passenger window didn't go up from the driver door switch, and the locks were a mess. I replaced the front bumper, grill and lights with a mix of new and junkyard parts.

While it ran well when I bought it, it quickly began to develop some problems. It's a 20 year old engine and was stored for years so some bugs were to be expected. I had a local performance shop go through it and they did a dyno tune as well. When done it put 238hp and 323 ft-lb torque to the wheels. The engine is not modified. The shop owner liked it enough he told me when I picked it up that he bought one for himself.

These pictures were taken over the summer. I've since added the door handle bezels and the SES light is now out.

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[WILWAXU]

Cool truck! Bet the t-56 is fun.

 

[s98gmc]

It is, especially now that's it's running well.

Here are a few more pictures. This is shortly after I bought it:

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Picking interior parts from the yard. I ended up throwing that grill away after finding a better one from a 96.

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After one of many days getting ready for paint.

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"New" bumper install. I found one from a 99 Suburban for $100. It's not perfect but far better than the one I had and they threw in the brackets and hardware. The price included removal (I bought it from a yard that doesn't allow pulling parts yourself).

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Running new wiring for the electric locks and mirrors. I didn't fully remove the dash, just tipped it enough to reach the conduit along the base of the windshield. I relocated the relay behind the glove box. You can also see the overhead console I pulled from another Suburban. I'm thinking of going back in the spring and grabbing the dash to have as a spare.

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[GMTMark]

Very nice!

 

[s98gmc]

Thank you.

My winter projects may (or may not) include reassembling the passenger door. The day I was putting it in storage the starter died. The day I picked it up from the shop it rained really hard followed by a quick drop in temperature. While I was out that evening the locks froze. The passenger door cylinder started to come apart while trying to get inside. I've currently got the door pulled apart but it's been too cold to put it back together.

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I also want to look at the cruise control and ABS. Neither work. I have a few more parts I want to try and find too, including an under hood storage box. I replaced the factory radio with an aftermarket that doesn't show the time. I bought a small digital clock that I want to install somewhere. I'd like to install one of these too:

https://americanpowertrain.com/i-23887142-reverse-lock-out-module-6-speed.html

There's currently a push button momentary switch on the dash, but it's a bit awkward to use. I have to reach through the steering wheel to depress it while engaging reverse.

I have my eye on this too:

https://ultra-gauge.com/ZC/index.php?main_page=product_info&cPath=1&products_id=94

My speedo seems to have an issue with the stepper motor. Around 70mph it will get stuck then sweep quickly to the correct speed. I may look into one of those companies that rebuilds instrument clusters.

The blower motor is kind of noisy too.

So I have a few potential projects for the winter.

 

[s98gmc]

With winter I haven't really done much, so not many updates since last time. I did fix the passenger lock and reassemble the door. While it was apart I installed some sound deadening material. I bought an under hood storage box and an extra dash bezel from a junkyard in mid December. I installed the box and my uncle used the battery tray for his 56 Ford Victoria. I installed a digital clock in the dash bezel, and stashed my original in a safe place in case I change my mind later. I also came across the before and after print outs of the dyno session. The Vortec 350 is stock. The only part to my knowledge that isn't original is the Y pipe, which didn't have cats when I bought the truck. I had a shop install cats shortly after I bought it so it would pass inspection. Drones a lot less too.

Before:

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After:

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[s98gmc]

I realized I haven't updated this thread in quite a while. Anyway, my GMC is parked for the winter. I drove it the last time this past Sunday. Just in time too. While it didn't snow here this week I did see some road salt.

For the most part I just drove it this season. I added around 2k more miles and it served well during a move near the end of May. I also took it to a couple shows.

Shortly after I posted the last update I had a leather shift boot made. It cost about $100 and I reused the chrome trim piece that came with the rubber boot I had originally. You can see in the pictures it's a bit warped. I've since straightened it and added a second ring underneath to add some strength, which I cut from a piece of scrap aluminum.

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I purchased a sliding rear window in July, which I had installed by a local shop.

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A couple days after having the window installed my brake lights stopped working. The hazard/turn signal fuse would blow when pressing on the brake pedal. With some help, we figured out it was the third brake light. After further tinkering I discovered it was shorting out on the outer skin of the cab. If I had the brake housing hanging by the wiring the lights worked, but would blow the fuse if it was installed. What I think happened is the sliding window is larger than the original. The outer edge of the window rubber extends under the bottom edge of the third brake light housing gasket. This caused the bulb socket(s) to come in contact with the metal cab, which was causing a short. I fixed it by cutting the opening larger. This is a 91 cab which would not have had this third brake housing originally.

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I removed that clock to the left of the column. It didn't keep time that well and was hidden by the wheel when driving.

 

[Derick]

Very cool truck