Hello I am trying to decide whether to get a Aeronose 7.3 Powerstroke or a 99-00 Super Duty 7.3 Powerstroke.

I want to get roughly 600lbft of torque out of the engine. Is that a hard number to get out of a Aeronose 7.3?

I like that the Aeronose 7.3 uses a mechanical fuel/lift pump where the Super Duty uses an electric fuel/lift pump. I am planning on retrofitting the engine into an older truck and I think the mechanical fuel/lift pump will be easier to plumb into my factory dual tank system.

I also like that the Aeronose 7.3 doesnt have an intercooler so I wouldnt have to cut up my radiator support for such a thing. However I want it to make roughly that much power as I will be often pulling a wrecker tow truck on a flatbed behind this truck and I want it to be able to go up most grades without loosing much speed and being able to get up to speed in a decent amount of time.

Kind of a second question which is a better transmission either the ZF5 or ZF6 and if I go with the Aeronose 7.3 could I retrofit the latter?

 

ZF5 or 6 will work if you plumb the lines to radiator.

Stock is 425 lbs torque
SD 7.3 is more but you need intercooler

 

My truck made stock 201hp and 376 lbft and it has a hard time driving down the road unloaded with just my camper in the bed. Its also supposed to have a 2 barrel intake and smog heads which it has non smog heads and a 4 barrel intake so in theory it should make more power than stock.

I liked how my dads 6.0s pulled however I dont want a 6.0 so I figure if I can make a 7.3 either Aeronose or Superduty version make about the same power or more I would be set.

I dont want an intercooler so I dont have to cut holes in my radiator shroud so that will limit me on some power im sure.

Why would a manual transmission need lines to the radiator?

 

to cool it

 

How would you even add a trans cooler to a manual? Not like it has an oil pump like an automatic does.

 

the ZF6 uses a trans cooler.

 

You do realize manual transmissions still have transmission fluid, right?

 

The ZF6 has an oil pump and cooler circuit in the Fords. ATF is spec'ed for the fluid. In GM trucks they use gear oil and no cooler. No idea why.

So this is for a swap into your truck now? I think you are limiting yourself a little with no intercooler and mechanical pump. I think both are needed to hit the power you want at safe EGTs. Also (experts can correct me here) its my understanding that the earlier 7.3 PS diesels had forged rods and changed to compacted graphite rods. Better for power adders. I'm not sure what the year range is for those.

Are you subject to emissions testing and such?

 

older 7.3 have forged rods that can go to about 550 HP
newer ones have PMF rods that wont hold up to 400hp

above stock, you have to monitor EGTs if you dont have an intercooler on a an OBS

 

The oil pump and cooling loop in the radiator for Ford's version of the ZF6 allowed for better cooling of the transmission, particularly when towing in overdrive.

Forged rods or not depended on the engine serial number. Serial numbers 1,425,746 and below, and between 1,446,713 and 1,498,318 are forged. Between 1,425,747 and 1,426,712 as well as 1,498,319 and above are powdered metal. That roughly corresponds to sometime around 2000 there was the brief run between 1,425,747-1,426,712 with powdered metal rods and then the units 1,498,319 and up were usually 2001s or later. But, check the serial number to be sure. However, 600 ft-lb should be fine for powdered metal as that's barely above the 525 ft-lb the 2002-2003 engines came with stock.

I had to make the decision between an OBS F-Superduty and an F-450 or F-550 Super Duty and came down on the Super Duty side as the Super Duty was simply a stronger, heavier truck. The aftercooled 7.3 in the Super Duty is stronger than the non-aftercooled 7.3 in the OBS, it is located in an easier to work in engine bay, the front axle on the Super Duty is noticeably heavier than that of an F-Superduty, the frame is heavier, the Super Duty ZF6 is stouter than the OBS ZF5, and the 19.5 wheels and big disc brakes to fit them are larger and stronger than the OBS equivalent. Plus the parking brakes are better, although not great. The OBS does look better and has the neat vent window. Plus the OBS has West Coast mirrors which just look weird on a Super Duty.

 

I did not know that the ZF6 had an oil pump that is very odd but I also work on 70s vehicles.

I didnt know any transmissions had oil pumps to be quiet honest on a manual setup.\

Transmissions im used to working with are T-18, T-19, NP435, T-10, and T-170 which do not have oil pumps.

I have 2 trucks I want to diesel swap.

One would be used as a tow rig for dragging around a 30-35' flatbed gooseneck with a camper at the front and a service bed underneath that.

The truck that would go behind that on the trailer would be my other diesel truck I want to swap which is a tow truck for rock crawling and trail running.

What I really dislike about the electric pumps is how big they are and they hang down super low at least on most of the ones ive seen which wont work for me.

I like the simplicity of having just a mechanical lift pump because its simple and also simplifies me having dual tanks so itll just pull from one tank or another depending on which way I have the original mechanical 3 way valve switched.

Intercooler I dont think theres is physically enough room for one in the grill and besides id rather not cut 4" holes into my radiator support.

I know nothing about egt's every diesel my dads ever owned or ones ive been around are bone stock.

California things but since my stuff is pre smog its not a problem so no emissions.

I was told about the forged/powdered rods by a friend of mine on instagram a few years ago he said the 94.5-00 trucks had forged and some 01's but the 01-03 had powdered.

I dont think it matters which rods I were to have id only like to get around 600 lbft out of the thing which id guess is probably 300-350hp.

Im not sure how much that would really be turning the engine up to make that power.

The Aero makes 210hp so in theory Id be turning it 90-140hp up.

If I went NBS it would be 235hp stock so it would be 65-115hp turned up.



Very interesting well I mean the radiator I have for the trucks have the transmission coolers for the autos anyhow so I could just hook that up not a big deal.

Any idea why they put powdered in some specific serials and not just randomly whatever was on the shelf?

Thats kinda what I was thinking that it didnt really matter which one I went with as im not trying to turn it up to make 1000lbft or anything of that sort.

I just want my truck to tow a loaded trailer that weighs roughly 14k lbs but also be able to get up to 65 in under a year.

Ive contemplated just getting an Aero 7.3 Crew truck since I really want a crew however its hard for me to decide todo that as my 70s truck would have basically no place for me to use it if im not using it as a tow rig.

Reason I wouldnt get a NBS is due to having to smog anything newer than 1997 in the state of California where I live.

I could register it out of state however if I get caught doing that and I end up having to register it here and then im stuck with a non smoggable truck.

Also cool factor of having a diesel swapped 1973 F350 140WB 4wd swapped truck on 37s.

 

The transmission oil pump is there to pump the fluid to the oil cooler located in the radiator, and is apparently a significant part of why it is allowable to tow in overdrive with a ZF6.

The Super Duty electric fuel pump is attached to the inside of the left C-channel frame rail underneath the driver's side of the cab. It is very well protected in this location by the bottom of the frame rail, it does not hang down.

Powdered rods were less expensive than forged and the initial run of powdered rods was apparently a trial, which is why they only did it on specific serial numbers. Navistar switched production to powdered rods once they thought the trial went well. Most report you'd never know if you have forged or powdered unless you start adding significant power. The powdered rods are said to be fine until you get to roughly 400 HP (about 800 ft-lb or so). Specific tuning to limit the amount of fuel dumped into the engine when it is at low RPM is a good idea. Ford rated the 7.3 with powdered rods up to 275 HP/525 ft-lb in the last manual-transmission models in the early 2000s.

A stock OBS or Super Duty 7.3 will pull a 14k trailer. I've pulled a little heavier than that with my stock F-450 and often it is on a 65 MPH four-lane highway. It is far from new-truck fast but it doesn't take a year to get to 65 MPH, I'd estimate about 20 seconds or so on a flat grade depending on how tall the trailer is and if you are driving into the wind or not. It accelerates better and holds speed going up hills better than loaded heavy trucks like dump trucks, box trucks, buses, and tractor-trailers so it's not the slowest thing on the highway by any means. The most I've seen somebody pull with a 7.3 was a Super Duty F-350 pickup pulling a 40' tandem dual gooseneck with 20 4x6 round hay bales, two rows of seven on the bottom and then one row of six on the top. Unless his bales were unusually light that would be about 30,000-35,000 pounds of trailer and bales. That engine was screaming along and he was going maybe 55 MPH on the 65 MPH four-lane highway.

I feel sorry for you dealing with California vehicle registration and emissions. It appears my F-450 is illegal in California as it's a pre-2010 diesel with a GVWR over 14,000 pounds. There is no emissions testing where I live, just a silly inspection where you pay the local tire shop $12 and they make sure you don't have burned out light bulbs, bald tires, a muffler scraping on the pavement, or brake pads or shoes worn to the backings and then they give you a sticker. I have seen a few of these stickers on trucks here as a joke:

 

I have an old 76 7.3 on 37's project I'll hopefully get done one day. Luckily I don't live in CA

 

I see, does that mean if I had a ZF5 your not supposed to tow in overdrive? I dont do modern trucks typically like I said I figured you could tow in any gear as long as the engine would move it.

Only reason I said that about the pump hanging down is that it seems just about every 92-97 7.3 truck I see has 2 huge filters hanging a foot below the frame rail I figured that had something to do with the lift pump.

I see, the last manual 7.3 with the powdered rods is probably all the power I would ever need in the truck.

Im not exactly sure how much weight I would be pulling behind it but the tow truck would definitely be the heaviest vehicle I would put on the trailer with the service bed and the camper at the front.

Service bed is only for tool storage and parts. My 73 truck is a single cab long bed so with the exception of the little room in the bed thats all the tool storage I would have so more the merrier.

That sounds like quite the load I dont think I could find that much weight around here to throw behind my truck.

The emmisions arnt to bad for me since most of my vehicles are pre smog so I dont have to typically smog anything.

I came across a 2001 F550 7.3 ZF6 4WD for 8.5k with 157k miles on it for sale which is very tempting but it would be something I would have to register out of state as you said its illegal.

Wouldnt be an issue until I get in trouble for it being out of state. I found quite a few of the F450/550s and they dont seem to carry nearly the value the 250/350 trucks do at least in California.

Guessing part of the value issue is due to the fact you cant register them in the state. Dumbest stuff ever.

Would be nice to just have a yearly inspection to make sure your vehicle is roadworthy but we dont ever get those here just smog checks thats about it.

That is one sweet truck youve got there!

Which 7.3 did you end up going with and what transmission/transfercase are you running?

Looks like a 05+ D60 setup in the front those seem to be pretty popular with 4wd converting these trucks.

My 73 is using highboy parts to convert it to 4wd so im still on the original F35 chassis but with highboy parts shoved into it.

Ive been looking for basically that exact bed that you have on your truck for my one 76 highboy farmtruck restoration im doing.

I need to get back onto that project been on the backburner since about November of 2024.

I had got the whole truck apart and sandblasted the whole chassis and painted it but I havnt gotten around to putting it back together yet.

I dont have a whole lot left on it thought. Need to replace the front leaf bushings in the frame and replace the floor pans then I can start making it look like a truck again.

I need to track down a 76-77 D44 Big Hub, D60 narrow frame rear axle, and a divorced NP205 for it.

Picked up a 71 360/NP435 setup awhile back I need to rebuild for it and after I get all the parts and a bed for it I think ill be ready to sell the truck.

 

Supposedly. I have a copy of the 1996 OBS F-series manual and it notes the driver is not to use overdrive when towing with a 5-speed manual. There were two 5-speed manuals available then, the M5 for the F-150 and ZF5 for the F-250/350/F-Superduty and it does not make a distinction between the two. There is also a bit of discussion online about whether or not you are supposed to tow in overdrive with a ZF5 specifically.

Oddly enough the manual for my 1999 F-450 makes no mention of not towing in overdrive, and the V10s still had the ZF5 until 2002 or so if I remember correctly.

That would be an aftermarket setup. The fuel filter on a Super Duty with an electric pump sits on top of the engine behind the HPOP reservoir.

The 1 1/2 tons around here are roughly the same price as the F-250s and F-350s for the most part, although prices vary wildly depending on condition and options. An '01 F-550 with a 7.3 and a six speed with only 157k miles here would be quite a bit more than $8500 unless it was in terrible shape.

Inspections do very little to say if a vehicle is roadworthy, there are all kinds of rolling scrap heaps on the roads and all of them got inspected within the last two years if they are over ten years old or have more than 150,000 miles. The requirements have been decreased over time and there is talk about finally getting rid of them as they didn't really accomplish what was intended.