6.4L Hemi vs 7.3L Ford Gasser-either in a Dually

[GonnaBuyaDually]

Hello. Looking for real world comparisons of these two drivetrains. I have had the 8 speed, so I know it is absolutely the bee's knee's, but, I am enamored with the higher output of the 7.3L Ford. I think the Ford 10 speed has a lot of promise, but I am not convinced that it is on par with the 8 speed. Same situation, but in reverse on the engines. I have a 5.7L hemi that has given me good service, but the 6.4L seems to be derated for the trucks. Why? The 485HP that they make in the SRT vehicles would do a lot to persuade me toward a Ram, but the 6.4L in the trucks only has 410hp. I looked at the torque curves of each 6.4L engine, and there are no answers there either. The higher horsepower SRT version makes great torque down low.

I am going to buy a 350/3500 dually crew cab long bed truck. I already put a deposit down on a Ford. I am getting very shakey about it though, as there is report after report about rear end/transmission noise and several people have posted pictures of low mileage trucks with metal contaminated rear end oil. Numerous people are saying that there is a grinding noise when shifting from 5-4 or 5-3 or 4-3 while slowing down. No one has pinpointed where this is coming from, there are NUMEROUS trucks that have already been back in to the dealer for this noise and several have been advised that new rear ends are needed. This is in ADDITION to a M275 Dana Axle recall that Ford already has underway due to thin castings at the spring mount.

I know my Jeep had DANA axles, do these Ram 3500 4.10 rears have Dana axles? I know that Dana typically makes excellent axles, but you can forgive me for being very cautious about this issue. There are already active recalls in place, and now there are numerous verified issues that Ford has NOT addressed.

I've had great luck with the prior 4 Chrysler/Jeep purchases that we've made, and I'm considering a fifth now.

This truck will be used primarily to tow 16-20,000lbs of tractor around a radius of about 70 miles of foothills at speeds of no more than 65mph.

Please comment as you feel necessary. Thanks.

 

[crazy jerry]

im at a total loss for words when somebody asks if these rams have dana axles. i better not say anything else

 

[ramffml]

That much weight is way to much for the 6.4, and probably the 7.3 as well. That is very much diesel territory.

 

[Fatbob Frank]

The 7.3 Ford motor is a real beast!
Too bad it's surrounded by a Ford everything else...

 

[GonnaBuyaDually]

im at a total loss for words when somebody asks if these rams have dana axles. i better not say anything else

For gods sake why? Sources show that Ram used Dana and AAM in the past, why should anyone have any idea what they're using in 2021 & 2022? It's not like they (Ram) come out and say it when you're on their truck configurator.

Spit it out, the cat got your tongue? And while you're at it, are there any major axle issues that I should know about before I cancel my Ford order and build a Ram? Any driveline issues at all? Besides the Aisin being a little clunky and rough (which seem to be the prevailing opinion all over the net).

 

[GonnaBuyaDually]

That much weight is way to much for the 6.4, and probably the 7.3 as well. That is very much diesel territory.

So let me elaborate on this a little.

I know a diesel would pull better. I understand that. I was hoping to get by with this big beast 7.3L and avoid the expense and clutter of diesel emissions. That crap is way outta control.

Even with knowing that I am in low elevation and only dealing with foothills, you think that I should be looking at diesels? My worst hills are only a mile long and probably 8% grade, most of them are just rolling hills though. This is really just a truck to pull around our tractors. My tractor is 7500lbs. My FIL has several that are 10k and 12k. We have a lighter equipment trailer, and a heavy 30' deckover gooseneck (probably 6-7k). I am going to buy my own trailer eventually, because I don't like the deck height of his gooseneck, and his equipment trailer is too short for my tractor with implements on the front and back.

So maybe in the future I'll be as low as 10k, but right now it's 14k-19k. You don't think the 7.3L & 10 speed are up for that?

I appreciate the comments. Right now we tow with 1998-2000 era 7.3L diesels in an F550, F350, and a 1998 Dodge Ram 5.9L 12v. None of the three tow vehicles have a crew cab, and none have more than about 200ish HP. Some of the hills cause speed drops to as low as 40mph due to the weak engines.

 

[GsRAM]

The 8 and 10 speed transmissions will help with the weight, but your still going from pulling heavy with diesels to pulling heavy with gas engines. Prepare for some level of disappointment with either as they both will be wailing 4k+ rpm on the grades to move all of that weight. I dont mind as I understand how gas engines work and make power and I love the sound of a V8 in the upper rpm range working.

But we see posts all the time about disappointment when folks go from diesel to gas.

North of 15k, your absolutely in diesel territory in my opinion, regardless of brand.

The 6.4 is a beast, I love mine and she pulls like a freight train, but I'm pulling a lot less weight than your talking about. There are reports of 6.4s with cam/lifter failures, but overall they are great trucks. I'm a Ford man, but have to admit this ram is gosh dang good. My favorite truck I've ever owned.

I don't think you could go wrong with either. The 7.3 is a beast also. But again, go into this knowing your in diesel territory (I think 10k on up is really, regardless of how they are rated) good luck

 

[Irishthreeper]

My ‘21 2500 6.4/4.10’s pulls our 10,500 loaded 5W great and I’d feel comfortable up to about 12,000 lbs. After that I probably wouldn’t.

 

[JerryETX]

Even with knowing that I am in low elevation and only dealing with foothills, you think that I should be looking at diesels?

I think as long as you get the 4.30 rear axle you'll be fine. A diesel would obviously have better towing performance and likely better resale BUT down the road who knows if diesel engines continue on the same path.

I'm sure you've seen this video on the 7.3 pulling 16k lbs. https://www.youtube.com/watch?v=4HiR9dxvGLY

Only issue I have with your decision is the word FORD.

 

[crazy jerry]

Sources show that Ram used Dana and AAM in the past,

you may want to find new sources. dodge ram hasnt used dana for nearly 20years

 

[GonnaBuyaDually]

you may want to find new sources. dodge ram hasnt used dana for nearly 20years

Well the Ram that I'm towing with is 23 years old. So what exactly is the big "gotcha" about asking axle type on a new Ram? I still don't get it.

 

[ramffml]

So let me elaborate on this a little.

I know a diesel would pull better. I understand that. I was hoping to get by with this big beast 7.3L and avoid the expense and clutter of diesel emissions. That crap is way outta control.

Even with knowing that I am in low elevation and only dealing with foothills, you think that I should be looking at diesels? My worst hills are only a mile long and probably 8% grade, most of them are just rolling hills though. This is really just a truck to pull around our tractors. My tractor is 7500lbs. My FIL has several that are 10k and 12k. We have a lighter equipment trailer, and a heavy 30' deckover gooseneck (probably 6-7k). I am going to buy my own trailer eventually, because I don't like the deck height of his gooseneck, and his equipment trailer is too short for my tractor with implements on the front and back.

So maybe in the future I'll be as low as 10k, but right now it's 14k-19k. You don't think the 7.3L & 10 speed are up for that?

I appreciate the comments. Right now we tow with 1998-2000 era 7.3L diesels in an F550, F350, and a 1998 Dodge Ram 6.7L 12v. None of the three tow vehicles have a crew cab, and none have more than about 200ish HP. Some of the hills cause speed drops to as low as 40mph due to the weak engines.

Towing 10k with the 6.4 will be fine. But keep in mind that a 2000 7.3L diesel came with 525 lb/ft of torque, which is still more than either of the two gas engines you're looking at. And the torque came on sooner as well.

I would never attempt 20K with any gas engine unless you're just going down the road for a few mins the odd time.

I get that you don't want to deal with the downsides of diesel, but for your use case this is literally the reason to get one. You kind of have to pick your poison at this point.

 

[GonnaBuyaDually]

This guy's video is what made me think the 7.3 will be sufficient. F250 with 3.55's.

My order is for a dually F350 4.30's.

7.3 godzilla towing 24k lbs through the rockies.

cat 420d backhoe tow test

youtu.be

He does grades and has a 32k gross. I think my situation will be alright. I hope.

 

[HEMIMANN]

Too late to this party, I see. Retired Mechanical Engineer here, with 34 years total in the power transmission biz of one sort or the other.

These guys in here know what they're talking about. North of 12k loads is too much for gassers, you'll burn them up if not on flatland in cool air and only tow on occasion. I use my 6.4 in front of a 7k trailer combo through 'driftless' (unglaciated) steep hills and that's plenty enough for it. Yeah, ok, I have 3.73 axle, but a 4.10 would get you to 10-12k load max.

You wanna pull big weight, you need diesel - not a screamer.

 

[GonnaBuyaDually]

This guy says it pulls better than his 2015 Duramax. I watched it and it pulled very well.

2020 FORD 7.3L GAS SUPERDUTY vs. DURAMAX

ＬＩＫＥ | ＣＯï¼ï¼ï¼¥ï¼®ï¼´ | ＳＨＡＲＥ | ＳＵＢＳＣＲＩＢＥTheMudbogger79 picked up a new 2020 Ford Super Duty with the new 7.3L gas offering, plus 10 speed trans. The goal was to ac...

youtu.be

 

[retired]

My buddy just ordered a Ford SD with 7.3 on Sept 20th and he just got the text saying that it is already built. He said on Monday it was going in to production and the next day they told him it was built. . So Ford is moving much faster than RAM. I would think the train ride is going to be faster too being it is not coming from Mexico. He said Ford (the company not the dealer) has been texting almost every day letting him know how the process was going. He has always been a Ram guy but wanted something different.

 

[cobracnvt]

I'd suggest researching all of the issues Ford is having with the 10 speed transmission. It pushed me to get the Ram 6.4 over the Ford. For example: https://static.nhtsa.gov/odi/tsbs/2021/MC-10189752-0001.pdf

 

[Sandevino]

Yes, a properly equipped 3500 dually gasser can pull 15-20k, but how effectively and more importantly, how safely? I had a 2020 2500 6.4 rated for 14k and let me tell you there’s NO WAY it could safely pull anywhere north of 10-12k anywhere but straight flat land. These YouTubers telling you this and that about their gassers beating older diesel’s may have some truth but I’d bet it’s more about ratings than anything else.

I‘ve been in the driveline business for nearly three decades and have seen enough to know to use the proper platform for the task at hand. I entertain the gas vs diesel discussion with fleet buyers every year and it comes down to intended use of the vehicle. Running around town, idling, crew haulers, hauling (2-3k payload), light (less than 10k) towing, industrial beds, etc and it’s 250/2500 or 350/3500 gas all day long.

Once the conversation turns to heavy hauling (12k +) the driveline recommendation turns to diesel.

 

[Toddz]

Hello. Looking for real world comparisons of these two drivetrains. I have had the 8 speed, so I know it is absolutely the bee's knee's, but, I am enamored with the higher output of the 7.3L Ford. I think the Ford 10 speed has a lot of promise, but I am not convinced that it is on par with the 8 speed. Same situation, but in reverse on the engines. I have a 5.7L hemi that has given me good service, but the 6.4L seems to be derated for the trucks. Why? The 485HP that they make in the SRT vehicles would do a lot to persuade me toward a Ram, but the 6.4L in the trucks only has 410hp. I looked at the torque curves of each 6.4L engine, and there are no answers there either. The higher horsepower SRT version makes great torque down low.

I am going to buy a 350/3500 dually crew cab long bed truck. I already put a deposit down on a Ford. I am getting very shakey about it though, as there is report after report about rear end/transmission noise and several people have posted pictures of low mileage trucks with metal contaminated rear end oil. Numerous people are saying that there is a grinding noise when shifting from 5-4 or 5-3 or 4-3 while slowing down. No one has pinpointed where this is coming from, there are NUMEROUS trucks that have already been back in to the dealer for this noise and several have been advised that new rear ends are needed. This is in ADDITION to a M275 Dana Axle recall that Ford already has underway due to thin castings at the spring mount.

I know my Jeep had DANA axles, do these Ram 3500 4.10 rears have Dana axles? I know that Dana typically makes excellent axles, but you can forgive me for being very cautious about this issue. There are already active recalls in place, and now there are numerous verified issues that Ford has NOT addressed.

I've had great luck with the prior 4 Chrysler/Jeep purchases that we've made, and I'm considering a fifth now.

This truck will be used primarily to tow 16-20,000lbs of tractor around a radius of about 70 miles of foothills at speeds of no more than 65mph.

Please comment as you feel necessary. Thanks.

I love the specs of the 7.3 and it has shown to pull great. Also keep in mind along with the rear end issues Ford had a massive recall on the 10 speed in their heavy duty line. The transmissions were failing at low mileage.

 

[Toddz]

The 6.4 is a beast, I love mine and she pulls like a freight train, but I'm pulling a lot less weight than your talking about. There are reports of 6.4s with cam/lifter failures, but overall they are great trucks. I'm a Ford man, but have to admit this ram is gosh dang good. My favorite truck I've ever owned.

I don't think you could go wrong with either. The 7.3 is a beast also. But again, go into this knowing your in diesel territory (I think 10k on up is really, regardless of how they are rated) good luck.

Most of my trucks have been Fords, and I agree my 6.4 Ram is the nicest truck yet. I love it.
As for the 7.3, they were bullet proof, but the 6.4 will out tow the pre-2003 versions. It has more gears (8 vs 4), and more hp/to (410/429 vs 210/425).