67 GMC 1/2 long bed, shortened, 6.0 4L80e swap

[T_Raven]

Bought this 67 a couple years ago and it's just been sitting while I finished some other projects. I bought a 5 lug trailing arm chassis and had a 6.0 and 4L80e laying around for it. I got tired of it not being at least consolidated so I pulled it in and started working on it. Got all the big stuff together and figured I might as well keep going and get it drivable.

Here's what it looked like when I bought it. Had a running 235 in it that I sold.









I like that the interior is all metal. My old 72 had a head liner and plastic door panels. I like this much better

[T_Raven]

I wanted 5 lug wheels and trailing arms so I picked up another chassis. One of the previous owners had already installed drop spindles, front air bags, and a notch kit in the rear. The wheels are nothing special but better than what was on it and will do for now.



I shortened the new frame. I know everyone usually Z cuts the frame. I went to Wyotech and we shortened a Ford there. They taught us to make diagonal cuts and opposite directions on each side. This is the 3rd frame I've shorted for my own vehicles and I decided I'd just cut it straight and see if it really matters. Also this frame is a little screwy so I'll eventually either shorten the original frame and put it back on that when I'm ready to make this thing a little nicer, or I'll build a tube frame from scratch.



I guess I didn't take one of the frame back together. Here's the cab coming off the old frame



And on the new frame



Starting on the bed









And I put the bed on the new frame. I also stole the tires of one of my TA projects to get it off the big LT tires that were on the wheels.



Then shortened the rear

[pat english]

Yeah usually the z cut or a step cut.But i dont think it really matters as long as you weld.Alot of coach companys straight cut them and box the inside.

Nice start though.the chop on the bed looks clean.

[T_Raven]

I put the 6.0/4L80e in and made mounts to locate them where I wanted them. I'm a Pontiac guy and I have plenty of Pontiac engine paint left over from other projects. This is an Iron head 6.0 so I painted the whole thing Pontiac blue



The whole idea with this truck for now was to put what I have together as cheap as possible. I made some simple plates to bolt between the frame and stock 6.0 engine mounts. I welded a piece on to triangulate them to the stock mount hole in the cross member as well. We'll see how they hold up once it's drivable but they'll at least work as a pattern to make nicer mounts if they don't hold up well. And I might decide I want poly mounts and redo all the mounts anyway.



I've parted out a lot of cars including a couple 4th gen f bodies so some of those parts ended up on this truck. These headers are some older cheaper 4th gen headers. I've kept them hoping I could make them fit this truck and with a mod to the driver's side collector they fit quite well.



The DS collector points to the side pretty far on 4th gen headers so I pie cut it and welded it back on



I cut off the A.I.R. and egr tubes and welded up the holes



I bought some v-band clamps for the collectors. The gauge pod is for another project



My tig welding skills still suck but I welded the flange to the headers



And I bought some mandrel bends to make up some exhaust

[T_Raven]

I like having a column shifter for autos and tilt is always nice. I grabbed a 1st gen s10 column from a pick n pull.



I removed all un-needed stuff from the column. I'll leave the dimmer on the floor and key on the dash. I'll use the wiper and cruise switches on the new column though. I filled in the key hole and installed the column











I ordered a gear indicator to mount on the column from speedway but haven't installed it yet

[T_Raven]

I haven't had anything with airbags yet and since this already had them on the front I figured I'd set up a cheap air set up. I bought some bags for the rear. With no lowering blocks under the axle and the bags between the arms and frame, I didn't like the pinion angle or the shock angle, so I made lowering blocks and mounts for the bags. I probably should've made holes in the frame for the air fittings but there was already one hole in the right spot to bolt the bag to, so I made the mounts to have the fittings on the bottom. Shocks are Belltech streets.



The drop blocks I've seen are like $80 for chunks of aluminum and 1/2" u-bolts. I used 2 1/2" 3/16" wall tubing which didn't cost much, and had a local spring shop bend me some u-bolts. I'm sure 1/2" ones work fine, but these are the same as originals and only cost me $40 and I got them locally.



For a pan hard bar I modified a spare f body pan hard bar to be adjustable. I'd like to build a watts link later so the axle stays centered if I raise or lower the suspension.

[T_Raven]

For the fuel system, since I'm keeping things cheap for now and using what's laying around, I used the pump out of a 98 Camaro tank. I cut the retaining ring piece out of the donor tank



And welded it into the stock truck tank



The pump assembly sits at an angle so that the pickup is close to the center bottom of the tank. I ditched the vent line that's in the pic since the cap is vented. I did pressure test it and only had to fix a couple pin holes. I'm not in love with the noise of the pump in the cab, but the exhaust and radio will drown it out lol. Eventually I'll put a tank under the bed.



I used the fuel lines from the same Camaro, bent them and cut them to fit. I cut ends off of Silverado lines at a local wrecking yard as the easiest cheapest way to connect to the stock rail and used flare unions to join the two. The Camaro only has a feed line to the rail and a return line from the filter to the tank with the regulator in the tank. I just removed the regulator from the pump module and I'm using the Silverado regulator on the fuel rail.



I also bought some 5/16" tubing and made some trans cooler lines

[T_Raven]

I've been a tech for 12 years and I consider electrical stuff a strong point, so re-working a harness is no big deal, just time consuming. I've reworked a few harness for other swaps and I always keep harness from the cars I part out to have extra wiring, fuse boxes, etc around. I have totes crammed full of harnesses lol. The harness I used came with a 6.0 I bought so I expected it to be a 6.0/4L80e harness. I guess it didn't come with that engine originally because it was a 5 speed harness. Luckily the guy that sold me the trans cut the connectors off and left them on the trans, so I had to add a bunch of wires to all those connectors. I removed all wiring that I wouldn't need. Used a fuse/relay box from a 4th gen f body. I didn't get a pic of the biggest mess of wiring I had with the harness laid out and 2 totes worth of wiring laying around too lol, but here it was apart



Everything soldered together, plug in the right spots and taped up



And all covered up with some split loom



Installed the harness. I used the stock engine harness body/fuse box connector. I used the starter wire to control the starter relay. And the keyed hot coil wire to control a relay that powers the fuses I wanted keyed power on. The temp gauge wire is connected to a stock 98 Camaro temp sender. All other wires I needed in the cab pass through a hole above that connector. I ran wires from the pcm into the cab for speedo, tach, ac request, and cruise so that I can use all of those later.



I built the harness so that I can hide the pcm inside the passenger fender and the fuse box will be mounted to the fender next to the battery



I've got 100' rolls of 2 sizes of double wall, adhesive lined shrink tube I bought on ebay. Much better than the stuff you can usually find locally. It shrinks 3:1 rather than 2:1 like cheaper stuff, and the adhesive lining makes it water proof which is nice under the hood.

[T_Raven]

I had the truck out of the shop a couple weeks ago when I needed to use the lift so I took a few pics of it with it's new length and ride height. So far I've just run airlines from the bags to the engine bay and put schrader valves on the ends so I can at least air it up. I haven't decided what to do to a compressor and controls yet but I'm pretty sure I'm going to use the Fourplay valve from Little Larry's. Seems like a better way to go than electric valves.

Here are the pics of it outside



I haven't been getting very good pics with this phone lately for some reason.





I think it looks pretty dang good compared to how it use to look. I want to make front and rear roll pans and paint/"patina" them to match, touch up the seams on the bed, and leave the body like that.

[boynton]

Good looking start. interested to see some better pictures of the engine mounts.

[T_Raven]

Originally Posted by boynton

Good looking start. interested to see some better pictures of the engine mounts.

Haven't had a chance to work on it lately or even put it in the air to take some pics. They are just pieces of 1/8" plate I bent at enough of an angle to bolt from the cross member holes in the frame to the holes in the stock Silverado mounts. I'll later get some poly SBC mounts and make new new frame brackets

[T_Raven]

Haven't had a chance to do much else, but I did shut off VATS and all unnecessary codes last week so I could start it. I needed to get a belt on it and coolant in it. Today I put this fitting in the t stat housing for the head crossover hose.

I see a lot of people putting them in the top of the water pump. That would be on the outlet side of the pump, and with these hoses normally going to the side of the radiator with the lower hose/inlet side of the pump, it made more sense to me to put it in the t stat housing.