1978 Chevy K20 longbed with nearly 500,000 miles! LS Swap begins!

[400/400]

Nice work on your build. It’ll be a cool truck for sure.

[Nick_R_23]

Thank you!

I picked up an air box tray and core support mount from the junkyard for $10! It didn’t fit anywhere near as well as I was hoping that it would, but nothing that a few cuts and welds can’t fix.



Ended up going about this far to fit correctly.



Factory battery tray bracket and 07+ core support bracket joined together.





Fitment in the truck!





Also fabricated a fender bracket for the other side of the air box tray.

[Nick_R_23]

More test fitting of the air box tray!





All parts painted, and everything bolted down!





The ECU will be mounted on its own bracket directly behind the air box. Test mounting where the best spot will be.

[Nick_R_23]

Alright, another weekend of progress!

A few more components showed up in the mail. These are 1/4-20 rubber mounts with a 5/8" diameter body. They will be used to mount the Terminator X ECU.



This is an OE connector for the Ford Fusion fan. This will be used when the fan harness is built and integrated into the Terminator X.



New grommets came in for the airbox from the dealer!



I fabricated an ECU tray and installed the rubber mounts.



Tray and ECU installed! Wires were also routed during this time.





Next project, accessing the cooling fan. I picked up a mating connector for the fan at a junkyard, and picked up a PWM generator from Ebay. These cost less than $10 and will be a handy little piece for testing equipment in the future!



The test harness is made, and the fan works!



I've also made a video showing the PWM operation of the fan and the basic wiring needed to make it function!

https://www.youtube.com/watch?v=hMEX...ature=youtu.be

As shown here, it pushes a piece of paper very well!



I also made the dedicated battery connections for the Holley ECU.



And finally, here's the engine bay progress so far!

[93M6Formula]

Coming together! Still love this build, you do good work.

[Nick_R_23]

Thank you!

I haven’t updated in a while due to some overtime weekends that came up, as well at taking care of those things that always pop up in life. But, during that time, I made a new score! Next in line for an LS swap



I was finally able to make it out to the powdercoaters and pick up the ceramic coated downpipes and midpipes. They turned out amazing, and should help out with durability and heat retention.



New flanged bolts and gaskets!



Drivers side downpipe installed



Passenger side downpipe installed



Both midpipes installed





Catalytic converters and mufflers secured!





And finally, tailpipes!





Next up, the final piece of the fuel system. I had to special order a package of 7/8” P-clamps.



I reused an extra battery terminal bracket I had, to mount the fuel distribution block and fuel pressure sensor.



Mounted to the side of the air box tray





Engine side fuel line ran with fire shield liner installed.



And a support bracket made for the line, and sensor wires.

[OutlawDrifter]

Wow, just made my way through this thread!

Amazing work and attention to detail for sure.

[400/400]

Nice work!

Always fun to pickup another project.

[Nick_R_23]

Thanks guys! It’s been a long while, but I’m finally ready for another real update!

In the meantime, I’ve picked up yet another project! A 1987 Chevy V10 that’s been turned into an off road truck. It needs a transmission rebuild, but I’ll post up another build thread once I have some time.



I’ve also been buying a few fun parts for the newer 2012 Silverado. It received new brakes, 28% tint to match the factory rear, 2014-2018 running boards, GM Accessory 22” wheels with Michelin Defender LTX tires, and the Denali/Escalade style side trim. The interior also received integrated Qi Charging in the center console.





Back to the ‘78, the engine bay and radio harnesses finally arrived from M&H!



The engine harness as it arrived. It will be modified to accommodate the LS components, as well as upgrade the power feed wire.



First, completely removed the fuel tank sender wire, as the dual tank harness includes this already.



Replaced with a quick connect for future servicing!



I’m rewiring the large +12v wires a bit to more closely resemble the 99+ wiring, since that is mostly what is used on this build. The alternator +12v wire was removed and a larger one installed with a fusible link from the power block which runs direct to the firewall distribution block. The +12v starter feed wire was removed entirely since the firewall block is now fed from the battery’s power block. The +12V ignition (distributor power wire) was cut and routed to a sub harness as a trigger feed for the Holley ECU. The coolant sensor wire was also ran down with the purple starter wire, as the sensor was moved to the passenger side of the block.



Completed harness with all modifications applied!



Harness routed and installed!





Good view of the larger power feed wire here.



Temp sensor wire, and the +12v crank wire peeking out in the background.



I also upgraded the battery terminals for the Holley ECU to solid brass, as the previous ones were cheesy and would loosen up on the battery.

[Nick_R_23]

I added a pair of vacuum caps to keep the studs from corroding at the junction block.



Next step, installed the radio!



Support bracket that always seems to be missing



Gauge cluster going in!



Now that the internal dash and engine harness were in, I started testing the electrical side of things!



I had trouble with the drivers rear taillight and license plate lights not working. I tried several bulbs, the brake and turn function worked fine. I dove into the harness and couldn’t get continuity through to the bulb sockets. Turns out, the LH taillight wire never got spliced in!



All the lights work!







I got sidetracked and installed a new master cylinder



Finally, the new dash pad from the parts truck. Not perfect, but a better match than blue!



Dash pad and gauge bezel installed!

[WilliamFd55]

That V10 is Nice! We need more pics.

[Honest Bob]

Nice progress! Rebuilding my np205 was probably my favorite part of my build.

[93M6Formula]

Updates?

[Nick_R_23]

Nothing really as of yet, I’ve been tackling a lot of other “outside” projects before winter hits. Been contemplating a small intake issue, but I haven’t had a chance yet to walk the junkyards to look for what I need.

[Nick_R_23]

FINALLY, an update! I’ve been stressing about this intake issue for so long, that I thought I wouldn’t be able to come up with a solution for it! I haven’t touched on it much, but this is basically what happened - when mounting the air box, in order for it to clear the hood, it had to be installed perfectly flat, as the height available in that area is limited compared to newer trucks. I didn’t think this would be an issue, but it “tilted” the airbox outlet enough that it misaligned about 10 degrees compared to the intake tube - it doesn’t sound like much, but the couplers available were so short and rigid, that it would pop the airbox out of its mount after sitting for a few minutes. This facilitated the need for a flex joint, but this would mean the MAF would need to be removed in order to create the room for a flex joint, but this left a 4.25” to 3.5” size difference between the airbox and intake tube. Not a big deal to delete the MAF (I had only retained it for the internal IAT sensor), but finding any combination of 3.5” flex coupler and 4.25” to 3.5” reducer has been eluding me…until now!

Today, the solution fell into my lap completely unexpectedly, and on the last vehicle I would expect to find it on - I picked up a 96-98 Chevy SCSB 2WD for another project. It came with a junk V6, but sitting on top of that engine was a perfectly sized 3.5” flex joint - also with a grommet-mounted IAT sensor! To say I’m more stoked about an intake part over an entire new vehicle is an understatement!

The 4.3L V6’s intake system:



The stock filter gauge and grommet removed, the 4.3L’s IAT and grommet installed perfectly in its place!



And finally, the 3.5” flex joint cleaned and “installed”. I still need a reducer, but reusing the MAF’s rubber coupler, I can buy a 4” to 3.5” exhaust reducer and join the two together! I will order the reducer, along with an IAT sensor extension harness now that I know where the sensor will be mounted, from Summit in the morning!

[Nick_R_23]

Summit package arrived today! The IAT extension harness came in.



Installed!



As well as the exhaust reducers. I ordered two different sizes just to see which fit better. Both would need a little massaging, but I think I can get one or the other to work!

[Nick_R_23]

After a few test fits with the exhaust reducers, I determined they weren’t going to work. So, I ended up just ordering a new, cheap MAF sensor to be the adapter. At $25, the quality definitely wasn’t there for its intended purpose, but since I’m not using it for anything other than an adapter, it’ll work just fine.



Installed! The intake is finally done!



I also made the electric fan harness, which runs to the battery and will be controlled by the Terminator X.







And finally, the (just about) complete engine bay!



At this point, I believe the to-do list has gotten pretty short.
I know I still need:

• New front and rear driveshafts made
• Install O2 sensor
• Run wiring for and install rear speakers and dome light
• Install new glove box door
• Diagnose non-functional oil pressure gauge (pretty sure it’s the gauge itself)
• Shim master cylinder from hydroboost
• Eventually go through the front axle and steering components
• New tires

Getting close!

[OutlawDrifter]

Good progress!

[Nick_R_23]

Well, here’s the biggest update yet! IT RUNS! I brought my laptop home and temporarily installed the O2 sensor, set a basic profile in the Holley software, and it fired up immediately! I ran into a few initial setup issues, including a fuel leak, but it runs great and holds 45 psi of oil pressure at idle! This video doesn’t do it justice, but it runs!


https://www.youtube.com/watch?v=ZhPRcW5gGqs


I also ran into a weird issue before starting the truck, I had an odd smell that seemed like a burnt electrical smell, but I couldn’t pinpoint it. After watching for a while, I finally noticed a faint puff of smoke from the wiper assembly. I popped the cover off and it seems like a coil melted! I’m not sure what would cause this, except maybe just an old part?

[OutlawDrifter]

Congrats on the start!

[layinrocker65]

Any concerns about the TermX being in the engine bay and it not being sealed?

[Corts60]

Nice progress buddy! Lots of work!

[Nick_R_23]

No concerns about the ECU in the engine bay. Holley states that it’s okay to mount it there, and it's not something thats going to see a lot of moisture anyway.

[Nick_R_23]

More new parts! I decided to ditch the original hubs because they were missing some small parts. Upgraded to the premium Warn set!









Also bought a new drag link set



And tie rod



The tires I ordered also showed up! BFGoodrich All Terrain in 305/70R16, or the closest metric equivalent to the current 33x12.50’s.

[Nick_R_23]

Thanks! It’s been a real busy summer, and finally found some time to get back to it!

Finished up the last bit of wiring and cable routing, securing the O2 sensor lead, clutch bleed line, and speedo cable.



Sourced a cleaner and straighter bumper for the rear!



Drivelines are being brought into town for either a rebuild or replacement.



The biggest part, updated the tune to include PWM fan control logic! Anyone care to critique my setup? I watched projectgatago’s video, and set it up the best way I could think, seeing as I don’t have a speed sensor on this truck. My thought process is that the fan should be off at 195F (thermostat temp) and running progressively faster at speeds above 200F, and ramping up significantly above 220F. I did RPM based instead of speed, one, because I don’t have a speed sensor, two, because the fan should remain off while moving anyway due to airflow over the radiator, and three, it acts as a safeguard to kick the fan on regardless of speed or engine running if the temp is that excessive. I haven’t tested this out with the engine running yet, as I wanted some feedback in case I screwed up.



I used Holley’s default Electric Fan #1 pin but repurposed it to PWM-



This box pops up when I click ‘Where Used’. Does the port have to be actively functioning (fan on), or did I screw up?



I set this to 190F just to ensure no need for the fan below that temp.

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