Big Ol' Engine Swap
Logistics Pro
Joined: Nov 2003
Posts: 4,371
Likes: 7
From: PA
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
That's what my next one will be. I already have an 85 Supercab chassis, just need to get a body to start putting on it. Bigger thicker frame rails, better rear springs, and slightly better ride vs the 68-72 model.
As far as 7.3 vs the almighty 12valve, IMO the 7.3 IDI is the superior engine. Wider rpm range, higher power stock before you even get to the turbo upgrade, smoother and quieter operation, and it still takes one wire to make it run. It starts much easier with glow plugs, of course, but that's just another pair of wires to the battery. The 12valve has a heater grid in the intake.
As an added bonus, people don't think they're made of solid gold. You can get a decent 7.3 IDI with 200-250k for around $500-$700, you're lucky to get a 5.9 for twice that.
As far as 7.3 vs the almighty 12valve, IMO the 7.3 IDI is the superior engine. Wider rpm range, higher power stock before you even get to the turbo upgrade, smoother and quieter operation, and it still takes one wire to make it run. It starts much easier with glow plugs, of course, but that's just another pair of wires to the battery. The 12valve has a heater grid in the intake.
As an added bonus, people don't think they're made of solid gold. You can get a decent 7.3 IDI with 200-250k for around $500-$700, you're lucky to get a 5.9 for twice that.
Thread Starter
|
New User
Joined: Jan 2015
Posts: 5
Likes: 0
Hey all. Thanks for your replies! (and sorry for taking so long to get back to you.)
I don't know what exactly I'm going to do; and at this point I'm not even sure when the build will be taking place (thanks yesterdays turn of events involving an idiot prius driver
).
I had considered simply rebuilding the 390 (they are indeed a damn good block) but wanted to do something a little more...unique?
IF I go the 390 route, it'll end up closer to 410
. And if I go that route, I'll close up on this thread and follow one of the other builds 
Also, thanks for the welcome John.
At this point, I'm looking more for information than anything else. OFC, with any good information comes with opinions, and I'd be glad to hear those too.
Crazed87bronco wow! That's a nice looking motor! The more I research this, the more appealing the 12v sounds for a diesel swap.
I don't know what exactly I'm going to do; and at this point I'm not even sure when the build will be taking place (thanks yesterdays turn of events involving an idiot prius driver
). I had considered simply rebuilding the 390 (they are indeed a damn good block) but wanted to do something a little more...unique?
IF I go the 390 route, it'll end up closer to 410
. And if I go that route, I'll close up on this thread and follow one of the other builds Also, thanks for the welcome John.
At this point, I'm looking more for information than anything else. OFC, with any good information comes with opinions, and I'd be glad to hear those too.
Crazed87bronco wow! That's a nice looking motor! The more I research this, the more appealing the 12v sounds for a diesel swap.
Posting Guru
Joined: Jul 2011
Posts: 1,650
Likes: 16
From: DFW Texas
That's what my next one will be. I already have an 85 Supercab chassis, just need to get a body to start putting on it. Bigger thicker frame rails, better rear springs, and slightly better ride vs the 68-72 model.
As far as 7.3 vs the almighty 12valve, IMO the 7.3 IDI is the superior engine. Wider rpm range, higher power stock before you even get to the turbo upgrade, smoother and quieter operation, and it still takes one wire to make it run. It starts much easier with glow plugs, of course, but that's just another pair of wires to the battery. The 12valve has a heater grid in the intake.
As an added bonus, people don't think they're made of solid gold. You can get a decent 7.3 IDI with 200-250k for around $500-$700, you're lucky to get a 5.9 for twice that.
As far as 7.3 vs the almighty 12valve, IMO the 7.3 IDI is the superior engine. Wider rpm range, higher power stock before you even get to the turbo upgrade, smoother and quieter operation, and it still takes one wire to make it run. It starts much easier with glow plugs, of course, but that's just another pair of wires to the battery. The 12valve has a heater grid in the intake.
As an added bonus, people don't think they're made of solid gold. You can get a decent 7.3 IDI with 200-250k for around $500-$700, you're lucky to get a 5.9 for twice that.
Logistics Pro
Joined: Nov 2003
Posts: 4,371
Likes: 7
From: PA
What don't you like with your current front MII suspension? If I ever did a 2wd bump it would have the MII for sure over a CV. I can't stand to see another one of those CV swap threads. There's nothing wrong with the 4bt I strongly like them in every way. Would be bad a** to pull up beside a 12v'r and beat him with your 4bt. That shines out a lot more IMO. What chassis/suspension would you want to go with if you could redo it all over again?
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
Well, you definitely have a point about the price; the cummins fetch a pretty penny. But that is probably because people keep paying it. The only reason I would hesitate to do the IDI and probably why they are so cheap is the problems they had with the blocks eroding. Isn't the compression ratio of those around 24:1? and isn't that why you had to do the additive in the coolant to prevent the cavitation or block erosion? Seems like that would be a crap shoot when trying to find one. And the cost could be moot point if you were not lucky. Regardless, I'm really becoming a diesel junky and for a budget swap I think that would be awesome. You got me surfing craigslist now. FORDSIX, what are people doing to the IDI's as far as turbo upgrades and anything that make more power? Anyone done a compound set-up?
Thanks. I say that because hindsight is 20/20. I wish I would have done a p-pump 12v and a different chassis / front suspension. Oh well though, I'm to the point of no return now:
Thanks. I say that because hindsight is 20/20. I wish I would have done a p-pump 12v and a different chassis / front suspension. Oh well though, I'm to the point of no return now:
The cavitation issue is majorly overblown. I have put over 30k on my swap with zero issues, getting upwards of 22mpg. The 360 got a best of 12, the worst I have gotten was 14.5 towing in the mountains. I actually have two 7.3s and a 6.9, although I haven't gotten the 6.9 to run yet.
Compression on the 7.3 is about 21:1, but there are aftermarket cams that bleed off some of that for running higher boost. There are a couple IDIs running over 400hp. I don't expect to get mine that high, I'd be thrilled with 300, which is also about 600ft/lbs so more than enough to move a truck down the road. Stock for most 7.3s is 180/375.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Just a FYI that I found out recently the Big Brown Truck UPS is going back to gasoline engines because they are cheaper to operate. 10 years or so back & beyond diesel was always several cents cheaper per gallon, but not anymore. With the vol of more expensive oil needed when changing, the fuel filters that have to be changed it is way more expensive. A bud told me a big oil change could run $90.00 including filters.
I am glad for you guys that own them and like them, but it is hard for me to see the charm, for what I use a truck for.
John
I am glad for you guys that own them and like them, but it is hard for me to see the charm, for what I use a truck for.
John
Posting Guru
Joined: Jul 2011
Posts: 1,650
Likes: 16
From: DFW Texas
Just a FYI that I found out recently the Big Brown Truck UPS is going back to gasoline engines because they are cheaper to operate. 10 years or so back & beyond diesel was always several cents cheaper per gallon, but not anymore. With the vol of more expensive oil needed when changing, the fuel filters that have to be changed it is way more expensive. A bud told me a big oil change could run $90.00 including filters.
I am glad for you guys that own them and like them, but it is hard for me to see the charm, for what I use a truck for.
John
I am glad for you guys that own them and like them, but it is hard for me to see the charm, for what I use a truck for.
John
. Fuel filter is 12 bucks. 200hp and 450 ftlb torque. Still no charm?????
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Hotshot
Joined: Oct 2002
Posts: 18,488
Likes: 22
From: The Big, Oregon
The EPA's "improvements" have made diesels a much harder choice. The emissions equipment that constantly breaks and causes a massive increase in fuel consumption is what the big cost is. I spent six months in Texas working on semis, and the most constant issue was emissions equipment.
Posting Guru
Joined: Jul 2011
Posts: 1,650
Likes: 16
From: DFW Texas
Yes, I know its hard to believe since your only used to early 70's gasser technology. There are guys with 4bt's running 33 inch mud tires on lifted 4x4's with non overdrive transmissions that get 22-24 mpgs. Matter of fact, my friend at work has a 70 chevy c10 long bed with a 4bt swap. Engine and tranny were pulled from the step van and installed in his truck with no upgrades to the engine. He has a th400 and a 32 in tall tire and a 3.73 rear gear. He drives 70 miles to and from work every day doing 70mph. His truck sees 24mpg 100% of the time. So yes, my 3.25 rear with a overdrive and and 32 in tall tire in a lowered short bed will see 30 pretty easily.
Logistics Pro
Joined: Nov 2003
Posts: 4,371
Likes: 7
From: PA
^X2 with F100 the 4BT's are widely known for getting crazy gas milage out of them. Even with mods to the engine big tires and no OD trans they are still seeing 20+ MPG. it varies from vehicle to vehicle and depending what you have done to the engine if your starting to make some real power then the MPG drops into the teens. I wonder what highntight is getting with his 4BT yota?
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Yes, I know its hard to believe since your only used to early 70's gasser technology. There are guys with 4bt's running 33 inch mud tires on lifted 4x4's with non overdrive transmissions that get 22-24 mpgs. Matter of fact, my friend at work has a 70 chevy c10 long bed with a 4bt swap. Engine and tranny were pulled from the step van and installed in his truck with no upgrades to the engine. He has a th400 and a 32 in tall tire and a 3.73 rear gear. He drives 70 miles to and from work every day doing 70mph. His truck sees 24mpg 100% of the time. So yes, my 3.25 rear with a overdrive and and 32 in tall tire in a lowered short bed will see 30 pretty easily.
John
Posting Guru
Joined: Jul 2011
Posts: 1,650
Likes: 16
From: DFW Texas
I pretty much take that as you are calling me a liar. I'm not sure why I care? Gimme a few months; Ill have it on the road. You can then shove that little shaky head, well, you know where.
Cargo Master
Joined: Feb 2006
Posts: 3,008
Likes: 250
From: North Pole, Alaska
Just a FYI that I found out recently the Big Brown Truck UPS is going back to gasoline engines because they are cheaper to operate. 10 years or so back & beyond diesel was always several cents cheaper per gallon, but not anymore. With the vol of more expensive oil needed when changing, the fuel filters that have to be changed it is way more expensive. A bud told me a big oil change could run $90.00 including filters.
I am glad for you guys that own them and like them, but it is hard for me to see the charm, for what I use a truck for.
John
I am glad for you guys that own them and like them, but it is hard for me to see the charm, for what I use a truck for.
John