1979 F350 Ford 7.3L Powerstroke Engine Swap

In this post, we will show and demonstrate the process taken to complete the 1979 F350 Ford 7.3L Powerstroke Engine Swap.

Welcome to another  project at the Auto Club.  We are  taking a 1979 Ford F350 single rear wheel four wheel drive truck and installing a 7.3L Powerstroke diesel that we removed from a 2000 Excursion.  This project has been going on for a while now and videos of our progress can be found at the JonesysAutoClub channel on Youtube.  Anyway here is a video that outlines the project.

The best part about doing a project like this is that it is not a very popular conversion and there is very little information out there.  Here is another video from our channel that outlines information you will need to convert the wire harness from the excursion to use in the older F350.


Back to the purpose of this post.  We have been moving alone with all the fabrication and modification needed to do this conversion and it was time to share how we hooked up the air intake.   We started with the stock excursion air box and battery tray as seen below.


2000 Ford Excursion air filter box

Because of space limitations, we were not able to use the Excursion’s battery tray.   We want to keep the stock filter box so we can always source a new filter.  Plus if we ever want to install a high flow filter we can just order one for the 2000 Excursion and put it right in.


1979 Ford F350 driver’s side battery tray.

The stock excursion filter box location was on the drivers front wheel well so the early truck battery box above had to go.


Above you can see the stock excursion filter box and the huge hole that we nee to fill.  If we don’t fill the hole then you will be pulling in hot engine compartment air and loosing power.


Filter box block off plate

We also determined that the stock location for the “Intake Air Temp” sensor would run right into our inner fender panel so we added the hole for the sensor into our block off plate.  We made a template and then cut the plate and hole in with the CNC plasma cutter.


Air filter box block off plate

We sealed and secured the plate to the plastic filter box with RTV and some pop rivets.  Some black paint will make this part look factory fresh.


Air filter box spacer and mount.

In order to get the geometry for the ducting and to secure the box to the fender panel.  We welded some nuts to a 2×1″ piece of tube.  Then we positioned and welded the tube to the fender panel.


Modified excursion rubber air duct

With the box secured to the inner fender and after some thought and parts reasearch we determined that we could do all of our plumbing with the stock Excursion rubber ducting and some 4″ madral bent U-bend exhaust tubing.   We shortened the rubber ducting and then cut the piece of metal tube to get us over to the air box.  Trial and error is your best option for figuring out  lengths and angles of the tube and couplers.


Final mock up of the intake air tube

After the intake air tube was installed we needed a way to get cold air into the air box.  With more 4″ tube and a custom mounting flange that we cut out with the CNC plasma we secured the cold air intake to the side of the air box.



Now you can position the coupler that will actually bring the cold air into the air box.  The easiestway to do this is to weld the tube directly to the core support and then cut the center out with an air body saw.  All of the metal tubes can be held together with some rubber sleeves and hose clamps that can be purchase from summit racing along with the 4″ u-bends.


The air saw will cut the sheet metal really well but will struggle to cut your weld.


Down the road we’ll add a screen to keep the big stuff out.








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