1978 Chevy K20 longbed with nearly 500,000 miles! LS Swap begins! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

400/400 · 05-01-2021, 11:37 PM

Nice work!

Always fun to pickup another project.

Nick_R_23 · 05-15-2021, 12:45 PM

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.

05-01-2021, 11:37 PM	#1
400/400 Registered User Join Date: Sep 2014 Location: Central MN Posts: 280	Re: 1978 Chevy K20 longbed with nearly 500,000 miles! LS Swap begins! Nice work! Always fun to pickup another project. __________________ -400/400 1979 K25 350/SM465/205/44HD/14FF 1985 K20 400/400/208/10/14 1987 V10 TBI350/700R4/208/10/10 '85 Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=643968

05-15-2021, 12:45 PM	#2
Nick_R_23 Registered User Join Date: May 2016 Location: Willow, Alaska Posts: 861	Re: 1978 Chevy K20 longbed with nearly 500,000 miles! LS Swap begins! 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.



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