Examining the Intricacies of an LS Swap in a Fox Body Mustang

People who say LS swaps are easy haven’t done many LS swaps.

Many people assume that just because LS swaps are common, they are easy, but that is not the case. In the video above from the Premium Fuel Mag YouTube channel, host Stu Gaskins walks us through each of the headaches that await anyone looking to easily drop an LS engine into their Ford Mustang from the Fox Body era.

The Introduction

The video above begins with Gaskins explaining his project to anyone who doesn’t frequent his channel. He is installing a fresh LS engine into his 1990 Ford Mustang and while he is aware of critics, he doesn’t really care. As he has worked his way through installing the LS in his Fox Body, he learned that many people believe that this is a simple swap, so he put together a video explaining each of the key roadblocks with the project.

He does point out that since so many people have performed LS swaps into so many different vehicles, there is a great deal of information available, but that doesn’t make the job easy. To help make the swap a bit easier by predicting the headaches, Gaskins walks us through each key area where anyone attempting this swap will need to prepare for troubles.

Will the Engine Fit?

One of the reasons that Gaskins picked the LS engine is because it is relatively small, so it will fit nicely in the tight engine bay of the 1990 Mustang. Newer Ford V8s with a dual overhead camshaft setup are much larger engines, making the install and future maintenance more difficult, but the LS engines are easier to install and work on going forward.

Electronics

Gaskins previously swapped a BMW M3 engine into his Mustang with universal electronics, but making your new engine communicate with your vehicle can be a major problem. You can either prepare for some wiring and electronics headaches, or you can go to a universal system that will plug-and-play with many engines and electrical systems.

Engine Mounting

In most cases, an LS engine will not bolt up to the factory engine mounting locations in a Ford or import. To address this issue, Gaskins installed a K-member for a 4.6-liter Mustang in his Fox Body while also installing 4.6-liter engine mounts on his engine. This required an adapter between the block and the mounts, along with the modifications to the mounts to make clearance for the headers.

Headers

Headers, or exhaust manifolds, are also an issue, as most companies who make LS headers design them to fit in a car that came with an LS engine. Those headers won’t fit in a Mustang, so you can buy custom headers or headers made specifically for an LS swap into a Ford, which was what has been done in the video. Also, once you have those special headers, there is a good chance that your exhaust system won’t fit, so you will need to have custom exhaust made or you will have to make some major changes to your previous pipes.

Engine Control

In order to make your LS engine run in a Ford Mustang or some other vehicle, you will need an Engine Control Unit (ECU) system to allow all of the components to communicate. The most popular option is an HPTuners program with the stock ECU and a computer, but Gaskins went with an entire standalone seutp from Megasquirt.

Transmission

Since the Ford engine wont bolt up to the Chevrolet LS engine, anyone attempting this swap will need to address that issue. The easiest option is to buy an “LS transmission” like a T-56 manual and make that fit in the chassis of the Mustang. Another popular option is a modified version of the CD009 manual gearbox from a Nissan 350Z, only because it is inexpensive to fix when things break.

The most expensive and difficult option is an aftermarket transmission and that is the direction being taken in the video above. Gaskins has opted for his Ford-style TKO600 transmission, which required him to get a custom bell housing, a special clutch and unique bearings for the clutch. He also has to come up with a solution for his clutch fork not reaching through the bell housing correctly. This requires either a modified fork or modifications to the transmission tunnel of the car.

Driveshaft

Once you install the new engine and transmission, there is a good chance that the driveshaft will be too long or too short and it might not work with your transmission. You will need to make sure that you have the proper yolk for the transmission and then you will need to determine the proper length of your driveshaft. In the case of this Mustang swap, he had to cut two inches to make the driveshaft fit with the independent rear suspension setup.

So, if you are considering swapping an LS engine into a Ford Mustang or anything else, the list above from this video offers a very brief look at the challenges ahead of you.

Join the LS1tech forums today!

Patrick Rall

"Before I was old enough to walk, my dad was taking me to various types of racing events, from local drag racing to the Daytona 500," says Patrick Rall, a lifetime automotive expert, diehard Dodge fan, and respected auto journalist for over 10 years. "He owned a repair shop and had a variety of performance cars when I was young, but by the time I was 16, he was ready to build me my first drag car – a 1983 Dodge Mirada that ran low 12s. I spent 10 years traveling around the country, racing with my dad by my side. While we live in different areas of the country, my dad still drag races at 80 years old in the car that he built when I was 16 while I race other vehicles, including my 2017 Dodge Challenger SRT Hellcat and my 1972 Dodge Demon 340.

"Although I went to college for accounting, my time in my dad’s shop growing up allowed me the knowledge to spend time working as a mechanic before getting my accounting degree, at which point I worked in the office of a dealership group. While I was working in the accounting world, I continued racing and taking pictures of cars at the track. Over time, I began showing off those pictures online and that led to my writing.

"Ten years ago, I left the accounting world to become a full-time automotive writer and I am living proof that if you love what you do, you will never “work” a day in your life," adds Rall, who has clocked in time as an auto mechanic, longtime drag racer and now automotive journalist who contributes to nearly a dozen popular auto websites dedicated to fellow enthusiasts.

"I love covering the automotive industry and everything involved with the job. I was fortunate to turn my love of the automotive world into a hobby that led to an exciting career, with my past of working as a mechanic and as an accountant in the automotive world provides me with a unique perspective of the industry.

"My experience drag racing for more than 20 years coupled with a newfound interest in road racing over the past decade allows me to push performance cars to their limit, while my role as a horse stable manager gives me vast experience towing and hauling with all of the newest trucks on the market today.

"Being based on Detroit," says Rall, "I never miss the North American International Auto Show, the Woodward Dream Cruise and Roadkill Nights, along with spending plenty of time raising hell on Detroit's Woodward Avenue with the best muscle car crowd in the world.

Rall can be contacted at QuickMirada@Yahoo.com