[Hellduster6.2]

I’m building a 79 TD for a friend of mine and looking to upgrade front and rear axles, brakes and suspension. Don’t mind finding a donor truck for parts but would prefer new stuff. Going for a drive and feel of a newer truck, and going to need to handle 707hp and 650tq if you know what I mean. Not going to be an crawler or even off the road all that much. Going for a stock(ish) look and ride height. Any help would be appreciated!

 

[jungle]

I wold say the D60 front & the D70 rear out of the 92-92 CTD trucks.
Jim

 

[W200’78]

If your doing what I think your hinting at, I want to see the process. Ive been wanting to see someone put a hellcat engine in one of these trucks. I dont have the means or skills (or money haha) to do it personally but would love to see someone have at it. Good luck and I hope you make a build thread, or atleast show us the final product.


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[Hellduster6.2]

I wold say the D60 front & the D70 rear out of the 92-92 CTD trucks.
Jim

92-?

 

[dodge82273]

cummins turbo diesel  or some correct spellin of that .. lol  92-3? i suspect not 100% sure ...

 

[jungle]

Yes a 1992-1993 Cummins turbo Diesel.

Jim

 

[Hellduster6.2]

Damn. That’s a narrow window!the hunt begins.

 

[Hellduster6.2]

If your doing what I think your hinting at, I want to see the process. Ive been wanting to see someone put a hellcat engine in one of these trucks. I dont have the means or skills (or money haha) to do it personally but would love to see someone have at it. Good luck and I hope you make a build thread, or atleast show us the final product.

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I don't post a ton but feel free to check the build at horsepower_northwest on Instagram

 

[712edf]

The Dana 60 front goes back to 75, but there were three different hub configurations (drive flange, external locking hub, internal locking hub). The internal type is usually deemed best & I believe that's the one in the latter Cummins trucks.

The Dana 70 rear was used other years too, but are direct fit 93-earlier.

Bucky

 

[RXT]

Question? Does this thing need to be 4wd?? It would seem to me that if you're doing no crawling or off roading, but you got over 600hp on tap, that you'd save a bunch of weight by eliminating the heavy and relatively unnecessary front axle.

Ed

 

[pc1p]

Kinda on the tails of what @RXT said, it likely doesn't need to have tons.

As a matter of fact, I'd be a set of 1/2 ton axles coupled with a rebuilt part-time t-case would help with traction some. Unless you're running some big meats, 1/2 ton axles can hold up fairly well to commonly installed tires on these rigs.

 

[neil4224]

Not to sway you one way or another but, what is the purpose of this build.  That may clear up a lot of our answers.  Are you 4 wheeling it? Rock crawling/Bouncing? Are you going to put in on the track or drag strip?  1/2 ton axles with the weight of our trucks may hold if they break loose, but if you were to ever "bite" I could see parts flying real fast. I am budget minded that is pretty much the reason all of us on here are often limited by the money in our pockets.  If you have the funds you may be best to start fresh and buy new units.  Especially with the luck you may have in finding exactly what you are looking for. If I had the funds I would buy 9 inch units and have them custom made to your specs. Yes they are fords, but it may be worth the investment.  That way you don't invest in rebuilding axles, just to waste your money when things go kaboom.  Just my .02.  Best of luck and please start a build thread. We would all love the hellduster to come to life. 

Neil

 

[Elwenil]

There is no way in hell I would run any considerable amount of horsepower through the stock 9 1/4".  Even with the band-aids available for the crush sleeve and backlash adjusters, it's still a C-clip axle with a bad pinion bearing design.  If you weren't wanting to go with 8 lug axles, I would be looking at a prepped Ford 9" at the least or maybe a D60.  Personally I would go 8 lug and swap in a later 14 Bolt with disc brakes.  If 4WD is not needed, then I would just convert the NP203 to part time, and then convert the stock D44 to 8 lug to match and call it done.  Then I would sit around and think about how long the converted NP203 is going to last under that sort of punishment.

 

[Hellduster6.2]

this is going to be a street driven vehicle 90%+ of the time. Going to keep it 4wd (decisions already made by owner) and also keep stock ride height. I’d like to stay away from Chrysler’s 9 1/4 and Ford 9”. As far as keeping the build moving forward we may have to just buy new, the probability of me finding axles from a 92-3 CTD in a Washington state is basically impossible. My main questions are what what front and rear axles would hold up to that kind of HP/TQ and is there anyone that makes any sort of kit (perches, springs, shocks) or big brake kits for say a Dana 60/70? Extensive fabrication, design, and engineering isn’t a problem. Just was looking for a good start since this seems to be the place where the first gen folks are.

 

[neil4224]

There is no way in hell I would run any considerable amount of horsepower through the stock 9 1/4". Even with the band-aids available for the crush sleeve and backlash adjusters, it's still a C-clip axle with a bad pinion bearing design. If you weren't wanting to go with 8 lug axles, I would be looking at a prepped Ford 9" at the least or maybe a D60. Personally I would go 8 lug and swap in a later 14 Bolt with disc brakes. If 4WD is not needed, then I would just convert the NP203 to part time, and then convert the stock D44 to 8 lug to match and call it done. Then I would sit around and think about how long the converted NP203 is going to last under that sort of punishment.

Agree with that one hundred percent on the 9 1/4. I would also be worried about the Dana 44, I know how crazy I can get sometimes and if I had that much power that is all I would want to do. But hey if your not paying the bills, let the owner decide on how much money he wants to drop and then drop again. As Elwenil stated the 203 probably isn't going to last either. I would recommend entire drivetrain be upgraded to probably custom built stuff. Don't know anything about modern T-cases, but 205's can be readily bought custom built. Don't forget driveshafts and ujoints as well. As you will find the bigger you go on one end you must build and match through to the other. Most of us learn that the hard way, killing budgets and projects along with the parts that fail.

Rearend choice would be limited to dana 60's at least. But again you are needing them custom built, and as Elwenil also stated you will need disc brakes (big ones on all four corners). I know the later heavy duty trucks have big enough rearends, but the problem is they are all driverside drop on the front diff. Hence the 93 cutoff year to find them/use. I know kits from large companies for brakes like baer, wilwood and the like are very limited in the support of our trucks/chargers/dusters with stock components. That is why custom is probably the only way to go.

Just an FYI, the rear-ends of the Dodge Demon have recently been exploding under launch conditions at the strip too. These are supposed to be prepped for their amount of power and abuse but after a year looks like they are failing too and seem to going into a million pieces. Check this video out,

Don't know if your client is boosting the power up on this hellcat motor or not. I bet your client will want too based on putting one into a 79 TD. So overkill on the build may be best option from the trans to the tires. Also how does this guy drive?

Best of luck and keep us updated on the progress and which way you go.

 

[username408]

If budget was no concern...
Rear Dana 60 EDIT: With the Trackhawk bolt pattern and rear brakes off a trackhawk

Front custom IFS based heavily on the SRT trackhawk.

I'd really try to use the trackhawk trans and tcase as it's set up to handle the power.  That may require floor modifications as it would put the drive shaft on the other side 

On a budget....
There is no room for budget if you want to use 707 hp in that chassis.  If you do budget it is for nothing but looks and sound.
Having run a 92 Cummins 4x4 to 110mph I can say that front end geometry and areo package has no business going that speed let alone faster.

Okay I'll give my input on some common beefy axles you might consider

8.75 Chrysler: They came under this chassis in the early 70's I don't remember the years, Really no stronger than the 9.25 with a weaker housing.  I wouldn't do it.

9" Ford: light weight, strong, reasonably cheap, fully customizable, the strength comes at the cost of power loss.

Dana 60: 8 lug in stock form that fits the truck easily, heavy Strong(on par with the 9" but doesn't take as much HP to turn though the weight of the 8lug outers likely offset that) lots of dif options.

Dana 70: heavier and stronger that the 60 with less Diff options.  Probably overkill.

Chevy 10.5 14 bolt: Similar to the Dana 70 but better.  If I break another 70 in my cummins truck it will get one of these.  It is my favorite HD pickup rear end.  If you get one from a 73-87(91 in square) it will be roughly the correct track width.

Really the front shouldn't have all that much load if it's properly set up and moving forward.  The real breakage would start if you can lift the front and have it under power when it lands.  If you have the traction to lift the front end you don't need 4x4 anyway.  So do whatever with that but I'd look into some really custom stuff with IFS at the power levels and speed potential this will have.

 

[Hellduster6.2]

If budget was no concern...
Rear Dana 60 EDIT: With the Trackhawk bolt pattern and rear brakes off a trackhawk

Front custom IFS based heavily on the SRT trackhawk.

I'd really try to use the trackhawk trans and tcase as it's set up to handle the power. That may require floor modifications as it would put the drive shaft on the other side

On a budget....
There is no room for budget if you want to use 707 hp in that chassis. If you do budget it is for nothing but looks and sound.
Having run a 92 Cummins 4x4 to 110mph I can say that front end geometry and areo package has no business going that speed let alone faster.

Okay I'll give my input on some common beefy axles you might consider

8.75 Chrysler: They came under this chassis in the early 70's I don't remember the years, Really no stronger than the 9.25 with a weaker housing. I wouldn't do it.

9" Ford: light weight, strong, reasonably cheap, fully customizable, the strength comes at the cost of power loss.

Dana 60: 8 lug in stock form that fits the truck easily, heavy Strong(on par with the 9" but doesn't take as much HP to turn though the weight of the 8lug outers likely offset that) lots of dif options.

Dana 70: heavier and stronger that the 60 with less Diff options. Probably overkill.

Chevy 10.5 14 bolt: Similar to the Dana 70 but better. If I break another 70 in my cummins truck it will get one of these. It is my favorite HD pickup rear end. If you get one from a 73-87(91 in square) it will be roughly the correct track width.

Really the front shouldn't have all that much load if it's properly set up and moving forward. The real breakage would start if you can lift the front and have it under power when it lands. If you have the traction to lift the front end you don't need 4x4 anyway. So do whatever with that but I'd look into some really custom stuff with IFS at the power levels and speed potential this will have.

hmm. I'm not so sure about that. I build numerous Mopars and almost always with a 8.75 rear and in fact have one in my Cuda that sees a lot of abuse behind a 6.4 Hemi and although it's well built, never given me one bit of an issue. Ever. I don't think a 8.75 would look right behind a Trail Duster, but they are not weak rearends. I think I'm going to hunt a Dana 60 front and 70 rear. They seem to be strong enough when built well.

 

[username408]

The 8.75 is not a weak rear end.  Neither is the 9.25.  Though I think 707HP and and 4,000lbs would really push the limits of either.  The housing on the 8.75 will be a weak point if you eliminate the pinion snubber and use something like cal tracks or 4 link.  I have seen the housings bend.

If you're stuck on solid axles go dana 60 front and the 10.5" GM 14bolt rear.  It has and an overhung pinion bearing and stronger carrier.  I'm pretty against building a Dana 70.