Ok guys. Before you ask, yes, I've google searched this topic till the cows come home, but no one covered the question that I specifically have.

So here's the backstory: My little brother, whose 14th birthday is this month, desperately wants a Ford Bronco as his first car once he's able to drive. So my buddy and I started to form a little plan to surprise him with something really neat and unique.... We've got two years to get it done, I'd like to hand him an envelope with the Bronco keys and enough money for a full tank of DIESEL FUEL on his 16th birthday

Picture this: a $500-1000 1987-1991 Bronco that needs a little TLC and clean up. Then picture a Ford F-250 from the same era with the 7.3L IDI diesel. See where I'm going with this? Everyone on the internet says it can "physically" be done and I don't doubt our abilities to stab a motor and transmission from the truck into the Bronco.

But what terrifies me is WIRING!!!!! My buddy does a lot of speaker and wiring work so he's a lot more competent than me. I think what's gonna save us is that we will have a donor truck to grab everything we need. My big question is what wiring are we gonna need to swap over when we put that big ol' diesel in the Bronco? Obviously the engine wiring harness will need to transfer, but is there behind the dash wiring that needs changed or anything obscure that I haven't thought about? Keep in mind we will not attempt this swap unless we start with a running, driving 7.3 IDI truck from the same era, if not same year, as the Bronco.

So if anyone's done anything like this, please tell me what nasty surprises you ran into or unforeseen issues you encountered. This project is still very deep in the planning phase and can be shut down as quickly as we dreamed it up. I value the opinion of my FTE "family", just please try not to laugh at me and tell me what a dumb idea it is. If enough people can think up enough reasons why not to do it, then I won't. But I've seen them out there and know it can be done, and want to give it a try if we can.

 

Here's my take, and I don't mean to be unhelpful but..... The wiring would not be the biggest obstacle (for me), My main concern is you're installing a huge, heavy engine that probably doesn't have any more power than a healthy 351, and much poorer throttle response. You're going to have to install bigger coils up front, and the handling is going to suffer. There is going to be a lot of cutting and custom fab work to be done. The oil pan of the 7.3 most likely won't fit in the Bronco chassis without a considerable amount of fabbing, and the exhaust manifolds are probably going to land squarely on the frame rails. Several years ago I saw a 150 of that generation with a 7.3, and the owner had cut away a disturbing amount of the upper frame flanges to make it fit. The whole thing was kind of a hack job. If you want to make a big engined Bronco, drop a 460 in it. It's a WAY easier installation and the wiring will be almost a non-event. Also the weight difference is minimal.

Yes, you could have the only 7.3 bronco in your part of the country, but it's going to be hugely impractical and a big heavy toad. That's my opinion and it's worth exactly what you paid for it !!
That being said, It's awfully good of you to be thinking ahead and trying to help out your little brother. I know some times they can test your patience, because I WAS the little brother -- about a hundred years ago. My oldest brother was a motorhead and let me in on a lot of wrenching sessions when I was a kid. Just keep an eye on your brother, I lost mine when he was 24 (I was 17) to an auto accident in which he was driving like an idiot, and it cost his life. Thank God it was a solo event and there were no innocent casualties. OK, enough of that. Good luck in whatever you decide.

 

My opinion, if you want a diesel Bronco, skip that 7.3 IDI turd and put a 4bt or 6bt Cummins in it. It would be less wiring and they are easier to work on and make power with, even a mildly built 4bt will run circles around an IDI and get better mileage.

 

Link to a really old build thread on the same topic: https://www.fullsizebronco.com/forum...-zf5-swap.html

 

Guys - thanks for humoring me on this one. It's always great to hear other opinions before you go and blow a crap ton of money on an idea that won't ever be "right". That said...

Well we figured to overcome the weight difference we would install the F250 suspension from the donor truck... I assumed (maybe erroneously) that the engine bay space for F150/Bronco, F250, and F350 were the same, but maybe they are not.

The 460 swap is intriguing though - the 460 trucks of the same year near me are a lot cheaper than IDI trucks. Can you tell me more about how that swap would work (aka wiring)? I read one thread about a 460 swap but they guy said it was very complicated and a lot of work. By contrast, many threads I've read have said that IDI swaps are fairly simple???? More experiences welcome!!!

I've heard about this swap, and of the potential of a Cummins in a Ford. But that's not what we wanted to do. We wanted to see what it would look like/be like if Ford ever offered a diesel in their Bronco - much like the Detroit Diesels offered in Blazers and Tahoes. That was the idea - a clean, factory level swap with working P/S, A/C, cruise, the works. Power, throttle response, weight.... none of that matters to me. The 7.3 IDI is what Ford offered at that time, so that is the engine we want to use. Call me ignorant or dumb but that is the plan. My satisfaction in the swap will come from creating a "factory diesel Ford Bronco" - not getting pushed back in my seat by a Cummins screamer.

 

If you are going through all the work to do a front suspension, and axle swap, the best thing to do would be to put a Dana 60 straight axle in out of an F350 of the same era. The F250 Dana 50 TTB isn't much better than the Bronco Dana 44 TTB.

 

We aren't planning an axle swap - just the 250 suspension components. Initially I wanted to do a 1-ton axle swap but I think that's a little over my head at this point.

 

The F250 uses leaf springs, so it would be just as much work to use the F250 suspension components as it would be to do an axle swap.

 

Why doesn't anybody just pull the bodies cut down the truck frame and drive line then mount the bronco body?

 

Now see this is important info for me to know. This brings up more headaches because I really hadn't planned on swapping the rear axle...... Then we get to driveline components, driveshafts, all kinds of things I really didn't want to do. Maybe we'll just accept that it'll be work to swap the suspension and then go for it. Options still open.

That's a bit above my abilities. I don't know if I would trust myself to cut a frame and put it back together. I'd rather swap a motor, transmission, and some suspension components.... For someone who has a lot of experience and a good shop to work in, I don't see why you wouldn't do that I guess.

 

So to conclude this, I think we'll forget about the swap idea for the time being. Instead, we'll take what the truck comes with and clean it up, give it a refresh, and maybe very mild speed parts. That'll be a heck of a lot easier and time efficient.

But thanks for everyone's input on this.

 

I really hope you stick to this plan, as a Bronco owner I can tell you a lot of things that would make me happy within a budget: Just get him a good, clean 94 or newer 351W (that will give you a MAF equipped truck, also preferably equipped with a manual transmission), replace the hub lockers with manuals (WARN or Mile Marker would be my picks), and maybe take some of that extra money you planned to spend for the swap and get these: Long tube headers, an Eaton E-locker, a good Winch (once again, WARN and Mile Marker come to mind), a set of decent AT or MT tires. You'll get a good performing Bronco that will be a great off-roader. Let us know what you finally did.

 

Encho - thanks for the suggestion. I'd like to get a 9th gen Bronco but what thing the little bro made clear is he likes the 8th gen (87-91). I think I've got a good line on a '90. I'm definitely looking for exhaust upgrades, but aside from that we'll probably just paint up the engine and re-gasket it.

Will most definitely keep you guys updated - be watching for my new (and final - I promise) Bronco thread once I pick one up!

 

I've got a 93 7.3 idi, and also a 95 Bronco, 351. Trust me , you want a 351.

 

You'll be doing him a favor by getting a later model, including the transmission if it's an auto, as later E4OD have several improvements that make it a lot more reliable. Better sensors and combustion management system, I don't think he'll have any objection about receiving any of those trucks anyway

In any case, get whatever truck you think will make your brother the happiest, just wanted to make sure you know there are some improvements you might be missing out, even the power ratings for the same engines are lower for the older model.