Hey guys,

Its been a while since I have been on here, so I needed to create a new account as the old one was gone. Anyway, I'm having a bit of trouble finding out exactly what is different about the 450 and 550's that have the "high capacity towing package". I currently have a 05 F350 cc, lb 4x4 SRW with the 6.0. Its been a great truck and treated me very well. The engine has a ton of work done to it and the trans is a fully built stage 3 from twisted. The wife and I recently bought a new toy hauler that is quite a bit heavier than our previous one, to the point where I am not comfortable towing it with my current setup. Will it pull it and stop it? absolutely, but now that I'm a bit older, married, and have a family, I don't want to risk the liability of an accident where I could be held liable because I am over weight. My plan is to find an f450 or 550 and transplant my engine and trans into it, so that I can keep my existing drivetrain that I put all that effort into.

I'd love to buy a newer truck with the 6.7, but I am very pleased with my current powertrain, and would like to be able to enjoy it.

Here's where I'm stuck....
On the tow ratings for the 05-07 f450 and 550, they are either rated at 17k, or 24k. The 24k rating states that that is only with the "high capacity tow package". I have searched high and low, and I can't seem to find a straight answer as to what is physically different between the 2 packages, so I know what to look for when buying my next truck. I tried running the vins of 2 different trucks, but since they were cab and chassis, it only states the basic info about them, and then lists all the options that they can be fitted with.

I seem to remember hearing something about the axles being different, maybe a s110, vs s135, but I'm not sure.

What say ya'll. I don't want to buy another truck and be in the same position.

FYI, my trailers gvwr is 19k and normally loaded for a desert trip its about 17.9K. Thats not including the 55 gallon water barrel that goes in the truck bed either.

Thank you.

Andy

 

The 01 F550 we had, had the larger towing capacity...can't remember what it was. The biggest difference was it had a larger gear housing with the 14.24" instead of the more common 11.25" out back with 4:88 gears, and I think a 5:38 was available. It would tow 24,000 lbs. or put 12,000 lbs. in the bed no problem. It was just limited to about 85 mph from what I remember, and the odd size 19.5" tires and wheels were F rated. We bought it with low miles...35,000 miles...with a dusted engine. I bought a Ford test engine with 500 hours on it and put it in there with some "upgrades" and it was a beast! I also remember the computer is different than the typical F250 F350 because Superchips had to make a special tune for it given the standard tuner wouldn't work.

 

Sweet, that's good to hear. My current truck is quite the beast, but I need to have better numbers on paper. I am a bit concerned about the ride quality of the 4 and 550 so I am going to work with Carli suspension and see if we can get a kit set up for the new truck to help with that. I am also planning on doing some fuel dually wheels so that I can run some all terrains to get some better traction and have softer side walls. I checked with twisted diesel who built the trans, and they said my trans will be a direct drop in, and I will have to check with gearheads, and have the tune adjusted to go with the new truck. This will be more of a dedicated tow vehicle than anything else so 85MPH wont be an issue for me. I feel that a 4 or 550 will serve me well, and I will feel safer taking my family in it when I am pulling my current rig on long trips.

 

Not sure what you can do about the ride, as the F450 and F550 trucks have the front straight axle with leaf springs...even with 4x2...like the 4x4 in the smaller trucks. I never understood why that spring pack was not upgraded as well. The rear spring pack is huge compared to the smaller trucks. Relative to the tires, I'm not sure you will want to deviate from the sturdy wall "F" load range with a heavy load. I bet with the newer 5r100 transmission...as compared to the 4r100 we had in ours...that extra gear will be a good improvement. Hopefully the smaller cubic inch 6.0L has some improvements as well for the task.

 

as far as i know, on the 05 and up f450's and 550's went to front coil spring suspension, which will greatly help with the ride characteristics. The engine has oringed heads, studs, aftermarket fuel system, turbo, injectors, intake manifold, etc, and the trans is a level 3 built by twisted diesel with billet shafts and some billet hard parts. It has a billet front converter built by Phil at DPC converters, and it also has a steel stator. Truth be told iv'e never seen the trans go over 185 even on 110 degree days. I do however have to watch my EGT's but going from 3.73 gears in the current truck to 4.88's in a 4 or 550, that engines gonna have a pretty easy time getting up to speed. Once the swap starts, ill definitely keep yall posted.

I plan on doing a 4x4 conversion while im at it, so I will pretty much have a heavier duty version of my 350 lol.

 

Ford switched from leaf spring, to coil spring in the front in 05. Don't know anything about the F-450 pickup as mine is a cab and chassis.
Wasn't able to find much about the HCTTP, appears to be a F-550 option in later models.
99-04 F-450 used the Dana S110 rear axle while the 550 used a Dana S135 axle.
Info I found says Ford changed the axles in 05 with the F-450 getting a Dana 80 with 10 lug hubs and the 550 getting the Dana S110 from the previous F-450.
There was mention of the HCTTP consisting of the 6.0 PS engine, 4.88 gears and a 4 pinion rear axle which would be the S135 as the S110 is 2 pinion, there was also mention of synthetic oil in the rear axle also with possibly a addition or upgraded trans cooler.
I have a 04 F-450 that we converted to coil spring front using a 07 F-550 donor chassis, both trucks had the Dana S110 rear axle, I think the 550 had one more spring but not completely sure now, swap was a couple years ago.
Coil spring front uses the upgraded Dana Super 60 axle with larger steering knuckles for a 9 ft tighter turning radius on my Super-cab.
F-450 uses 6000 lb coils while 550 has 6500 lb coils, we opted for a set of 5600 lb coils from a F-350 crew for a softer ride in the front, this also lowered the front about 2 inches, 450/550's set high in the front and I like the lower stance it has now.
One could drop down to the 5400 lb spring for a near F-250 ride and add a set of lift blocks to gain height if they wanted.
For the rear air ride suspension is about all one can do to soften the ride, the spring suspension on these trucks were made to haul weight and that means it's going to be stiff.
Not a lot of options for wheels that will fit the 10x225mm bolt pattern, 19.5 wheels barely clear the massive disc brakes these trucks have so don't plan on anything smaller.
The brakes along are worth the upgrade to a F-450/550 if one does much towing.
These trucks are heavy, mine weighs 9500 lbs with the custom hd steel bed, a lighter steel or aluminum bed could make it up to 1000 lbs lighter.
Most of my towing is local hauling hay and farm equipment with gcvw's of 25-29,000 lbs.
10,000 miles on the truck last year, 1500 miles empty truck, the rest of the time it was working

 

Thats awesome, thank you guys. Im excited to get this project rolling. From my reading, it looks like the dana 110 can take upwards of 14k lbs, so it sounds like either truck hcttp or not will be ok as far as axle weight is concerned if i were to be pulled.over and weighed. I plan on converting whatever truck i end up with to 4x4 if it doesnt already have it, and ill.do upgraded pada, rotors, and lines while.im at it. I also plan on replacing all the suspension components on the donor axle before it goes in the truck. Im excited to have the giant brakes that the 4 and 550.come with as my toy hauler is a big heavy pig.

I really appreciate the info on spring weights. I will definitely consider using lighter coils up front for a better ride.


How did your 450 tow with those 488.gears?

 

Honestly I didn't tow much with the 4.88's, I'm sure they would do fine with a higher reving PS diesel, but the 6.0 died a early death in my truck.
At 95K miles the egr cooler popped filling the engine with coolant, blew out #8 cylinder wall, bent the rod, damaged and lifted the head making the engine a complete pile of junk.
I bought the truck not running knowing it had mixed fluids and a dead cylinder but didn't know the extent of the damage.
Once known we nixed the repair plan and did a 5.9 Cummins conversion.
Because I do mostly local hauling I spend a lot of time in 5th gear with the ZF6 tranny, 55 mph with 4.88's was to many revs for the slower turning 5.9.
After a few thousand miles we pulled both diffs down and swapped in a set of 3.73's, gears for a S110 are very costly.
If I were doing a lot of interstate towing I would have opted for 4.10 or 4.30's to better utilize 6th gear's .72 ratio.
Regardless of the engine powering my rig it does a good job, handles the loads with ease on and off road and no breakdowns since the conversions were completed.
Plus side is if I need slower gears being 4x4 I simply shift the t case to low range.

 

Not to hijack this thread, but what did the swap cost if you don't mind me asking? I've been curious about replacing the 2v 5.4 in my '99 with a 5.9 at some point or another.

 

Not sure of exact price for just the conversion, probably around $3k for parts plus the engine, but I was very particular about the install, wanted it to look like OEM install.
Used core engine, complete rebuild with a few performance goodies, conversion parts, drive shaft rework, clutch and miscellaneous parts, also did the coil spring front conversion while the engine was out.
Total cost once it was on the road was around $10k plus the $6200 I paid for the truck, at the time we did the conversion the truck NADA value was $15,900 so I wasn't to upside down in the investment
Keep in mind other than engine machine work and drive shaft rework, all labor was done by me and a nephew.
Cost would have been double or more to have it done at a shop.

For some reason my computer hasn't let me load photo's for the last few days.

 

Im gonna have to do some serious thinking lol.

 

Finally able to load photos again
This is truck before front suspension swap



After coil spring front swap
Had to use donor trucks fenders with flares to cover tires due to wider track.




Engine swap, used 7.3 cooling to remove 6.0 degas bottle from firewall

 

Dude, thats awesome. Great job. Hows she run

 

Thanks!
Runs good, not as snappy as a 6.0 but has more torque for towing
Have it set to 325 hp but is making 800 lb ft of torque.
I can turn it up to around 400 hp but can't control the egt's at that level when towing.