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Terminator X Install: LS Swapped '86 C10

12/15/20 1 Comment(s) Customer Rides,


John R.’s LS Swapped ‘86 C10 with Terminator X EFI


Check out this stunning LS swapped 1986 C10 powered by the Holley Terminator X EFI system built by our friend and Awesome Customer, John R.'s.


As a native of Maine, John was able to finish up his Terminator X install this fall and put about 100 miles on the system before the colder months start to settle in. John is a long-time auto hobbyist with this C10 build being his 8th or 9th project to date. As a self-proclaimed old-school guy, this is his first build with EFI and with that being the case, John was looking for an EFI system that wouldn’t require a lot of tuning, leading him to the Terminator X, known for its self-tuning capabilities.


Background on the Build

When John bought the truck in 2016 it had a 350 engine and a turbo 350 transmission. The next spring he swapped the engine for a pretty well-built 406 small block producing over 500 hp with a huge cam.


350 engine


406 small block Chevy


406 small block Chevy


Following the 406 swap, John converted the transmission from an automatic to a T56 Magnum 6-speed manual transmission in 2017.



LS Swap

John really enjoyed driving the truck with the 406, but within a couple of years frustration was setting in from having to deal with rear main leaks and other issues, so he decided in 2020 that it was finally time to go for the LS swap.
John found a 2008 LY6 6.0 with 65,000 miles in a Silverado that he would use for the swap. This came with a stock bottom end, stock heads, but with a Texas Speed Stage 2 cam and the supporting valve train mods. He stuck with the truck intake allowing him to keep as much from the old motor as possible and went with 50LB L96 Flex Fuel injectors (GM #12613412).

Up next...EFI!

John is very pleased with how plug-n-play the Terminator X has been as everything has been essentially headache-free to this point. He did mention that he ran into one minor issue in setting the throttle blades correctly, but otherwise the install of the EFI system has been very smooth.

The original ECU was located in the glove box of the truck and with a small modification became a perfect place to mount the Terminator X ECU.



John went with the Tanks Inc. EFI Fuel Tank System with the 400 LPH fuel pump, plumbing in new fuel lines, the feed and the return line.



John decided to go with an electric fan and loves how well the Terminator X controls it with the dual fan control.


He’s also added Holley Tall LS valve covers and the Holley Coil Harness.


EFI Components:


Admittedly, John was a little nervous about the first start, but when he turned the key the engine cranked three times and fired right up. He has found the Terminator X to be reliable in both warm and cold weather, one of the reasons he is glad to be running EFI instead of a carburetor.


Although John hasn’t had the chance yet to get it out to the New England Dragway, he finds the engine far more responsive than the 406. And where he was getting around 6 mpg around town with the 406, he has been getting 10-11 mpg with the LS and Terminator X combo and he expects that will be 12 mpg around town next year.



Dakota Digital Gauges

John decided to go with Dakota Digital gauges in the dash and is extremely happy with how well the gauges integrate with the Terminator X. This is letting him display the fuel pressure in the message center of the gauges.


Overall Impression of the Holley Terminator X EFI System

“I could not possibly be happier with how well everything worked right from the very second I did the initial wizard.”


“The way that Holley terminated all of the wiring connectors was spot on. The only one that I had to change due to my personal taste was the fuel pressure connector because I have a transducer at the back of the engine coming off the fuel rail, so I had to open the harness up bring that back to come out earlier in the harness, but other than that everything was very well placed.”



Suspension Mods

At the time John purchased the truck, it had already been lowered with DJM drop spindles in the front and a DJM flip kit in the rear, but he did make further modifications to the suspension and brakes in 2018 and 2019.


Front Brake and Suspension Mods


Wilwood D52 calipers, Classic Performance Products drilled & slotted rotors


Belltech front sway bar, Classic Performance Products tubular control arm kit with coil overs


Rear Brake and Suspension Mods


Wilwood rear disc brake conversion kit, Cal-Tracs and QA1 adjustable shocks


Belltech rear sway bar kit


More Pics...






1 Comment(s)

John Reynolds:
02/16/21, 01:34:26 PM

Thanks for the outstanding write up on SLO-C10 Joe! It's been the most comprehensive project I've ever done as an automotive hobbyist. I'm pretty decent with a wrench but as you mentioned in the article I really have no ability when it comes to tuning and no EFI experience at all. Enter the Terminator X system and I can say that the LS Swap and EFI conversion process was truly plug and play because I chose to use the Terminator X system.

For any of you old school carbureted engine curmudgeons like me who are finally stepping into the 21st century, I would highly recommend using this system and also, possibly even more importantly, make EFI System Pro your source for all of your EFI conversion needs!

Chris Myer:
02/18/21, 02:49:02 PM

Our privilege entirely, John! Thanks for your response and for letting us be a part of this amazing story!

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