'72 GMC K25 build 454/4L80e

[superchevy]

frame mod for exhaust pics

[superchevy]

Now I was able to set the engine in without exhaust clearance issues.

[superchevy]

With the mock-up block in place, I bolted the 4L80/t-case in place to see where the trans crossmembers would need to be moved rearward to compensate for the 4L80's longer length over the stock T350.

[superchevy]

The cab, fenders, and core support came back from the paint shop. We set the cab back on the frame, and I assembled the front clip sheetmetal.

[superchevy]

With the front clip assembled, it was time to work under the hood...install the Alan Grove brkts and engine accessories. Then the custom aluminum radiator/shroud/dual fans. Got the new engine and front light harness installed. Wired up the DUI custom-curved HEI. Installed the new battery tray and wired up the fans/relays behind it. Fabricated a TPS switch swicth mount and accuator for the custom tuned Sean Murphy-built 830cfm quadrajet. Installed the completely restored and replated master cylinder/booster/brackets, as well as the restored heater box. Lots of plumbing and wiring going on, lol.

[superchevy]

After I installed the new A/C condensor, I was worried it was to "bright" in it's natural aluminum finish and would show through the large grille openings, so I painted it black with radiator paint.

[superchevy]

With the majority of the underhood stuff done, it was time to turn to the interior. First up was installing the FatMat soundproofing I bought on ebay. I put it all along the firewall, floor, rear of cab, and inside the doors.

[superchevy]

pics

[superchevy]

It was time to install the headliner. Since this truck is a Sierra and not a Sierra Grande, it did not originally come with a headliner or the holes for the headliner trim. I decided to glue it to the roof using liquid nails. I used some cut 2x4's to brace it up overnight.

[superchevy]

It was time to install the new dash wiring harness. Every harness on the truck was replaced with a new M&H harness and I highly recommend them. The heater box was media blasted and painted a satin black. I got lucky and scored an NOS heater control unit, as well as an NOS ignition switch and most of the other dash switches. The dash and gauges assembly is all new. The tilt column is originally out of a '72 Cheyenne. I sent it out and had it completely rebuilt/restored.
I also mocked up installing the TCI transmission controller in the center console.

[superchevy]

pics

[superchevy]

The dealer installed underdash A/C unit was completely disassembled and restored by a friend of mine to as new condition. I had the original A/C bezels re-chromed and reinstalled the unit. It looks great.
After the underdash A/C was installed, I installed the glove box and glove box door.
I set the factory bucket seats in place to get an idea of how they would look.

[superchevy]

Due to the longer 4L80e trans, the transfer case is 3" further to the rear than stock...combine that with the 2" body lift, and you get a transfer case shifter that is too low and has a much longer throw than stock. I had to modify the stock trans hump; first by elongating the cover to allow for the longer shifter throw, then making a cardboard template, then cutting the some sheet aluminum and riveting it to the cover. Next I fabbed up a steel trim plate that will screw through the carpet...I had it chromed...it looks pretty good.

[superchevy]

pics

[spike38]

Originally Posted by superchevy

Due to the longer 4L80e trans, the transfer case is 3" further to the rear than stock...combine that with the 2" body lift, and you get a transfer case shifter that is too low and has a much longer throw than stock. I had to modify the stock trans hump; first by elongating the cover to allow for the longer shifter throw, then making a cardboard template, then cutting the some sheet aluminum and riveting it to the cover. Next I fabbed up a steel trim plate that will screw through the carpet...I had it chromed...it looks pretty good.

Looks great! Are you going to put rubber under the plate from both sides,
To help close the gap.

Spike

[superchevy]

Thanks Spike,
Yes, there will be a small rubber gasket between the cover and the carpet, and a friend of mine has made a custom shifter "boot" out of some black leather...it will go between the trim panel and carpet.

[superchevy]

Wow! It has been a long time since I updated this thread, so here we go.
Before sending the truck out to paint, I needed to mock up the front bumper and grille. Due to the 2" body lift, the front bumper brackets had to be cut and welded to position the bumper correctly. After I did this, it was time to trial fit the beautiful aftermarket grille and tie bar. I had the original grille surround "eyebrows" rechromed, as well as the original headlight bezels.

[superchevy]

How about we take it for a drive!
After everything was mocked up, it was time to take the truck to the paint shop. I had my exhaust guy come over and bend up a couple of head pipes that I could bolt to the exhaust manifolds , attach some glass pack mufflers, and after checking and re-checking everything under the hood, I was able to fire up the engine and break it in. Happy to say everything went smooth, and even though the engine has a roller cam, I went ahead and ran her about 20 mins...even the electric fans came on correctly...I love it when a plan comes together, lol.
With the truck now under it's on power, it was time to disassemble everything in prep for paint.
It was time to drive her out of the barn for the first time! I managed to get up to second gear around the yard, before putting her on the trailer and heading to to the paint shop.

[superchevy]

3 weeks later and it was time to pick her up at the paint shop.
First pic is at the paint shop and second is back home.
I had to back her onto the trailer as front wheels/tires are to wide to clear the fenders...it's pretty cool to just back onto the trailer without putting the ramps down, lol!

[superchevy]

With the truck back from paint it was time to assemble everything. It's so much fun to finally assemble everything and install all the shiny stuff! First up was the grille, grille eyebrows and headlights. Also the sidemarkers, side mirrors, and GMC nameplates.

[superchevy]

Now time for the upper side trim. I was able to locate a complete set of NOS upper side trim and tailgate trim with all the NOS clips...it was VERY expensive, lol, but the fit is perfect.

[superchevy]

more side molding and eemblem pics...also notice the one-piece windows!

[superchevy]

The truck is 99.9% done now. I need to snap some more pics and put them up.

[72chevyfleet]

that is my dream truck a nice looking clean 4x4 i would just drive it because it looks cool

[mjensen]

That looks awesome! It has the exact same stance as I would like with mine. Great job!