Should I expend in a 742 third member or in a Dana 60 whole axle?

[lucascosta21]

Hi guys,

My 68 has a 440ci and I swaping it auto trans for a 4-spd. Originally it came with a 318 and a 741 third member which I suppose has a long ratio (I didn't meet yet my car, so I didn't know the ratio exactly but I can imagine that is low due to the auto trans column) and, as I'm changing the transmission, I would like to improve also the rear end.

I want to let it with 3.73 or 3.91. I've been consulting guys from Mopar Madness and they suggested me do not expend in my 741, but swap it for a 742 or 489. They sent me an offer for a complete 742 kit with sure grip includded of $1600.

Now my question is: What is the best to do? Go on with this 742 kit or change everything for a Dana 60? How much I will expend with a Dana 60?

*In the future I intend to upgrade my carb for a six pack.

Do you suggest any reliable place ou guy who works with Danas?

Thank you.

Lucas

[DAY CLONA]

Go with a DANA 60 don't waste time and money on the 8 3/4 rear esp with a 4 spd, contact www.doctordiff.com reputable company to deal with, the owner Cass is very knowledgeable and will steer you in making the right choice

[cdr]

Go with a DANA 60 don't waste time and money on the 8 3/4 rear esp with a 4 spd, contact www.doctordiff.com reputable company to deal with, the owner Cass is very knowledgeable and will steer you in making the right choice

  X2---------X3--------------X4     

[lucascosta21]

Go with a DANA 60 don't waste time and money on the 8 3/4 rear esp with a 4 spd, contact www.doctordiff.com reputable company to deal with, the owner Cass is very knowledgeable and will steer you in making the right choice

How much do you believe I will expend?

[cdr]

Go with a DANA 60 don't waste time and money on the 8 3/4 rear esp with a 4 spd, contact www.doctordiff.com reputable company to deal with, the owner Cass is very knowledgeable and will steer you in making the right choice

How much do you believe I will expend?

mine was 2800.00 shipped, no brakes,but has the more pricey S-Trac Differential. DR Diff is great !!!

[c00nhunterjoe]

Depends on your personal abilities, capabilities, and or local shops. I built my own bullet proof dana for under a grand less brakes.

[Midnight_Rider]

Depends on your personal abilities, capabilities, and or local shops. I built my own bullet proof dana for under a grand less brakes.

Is there by chance a thread buried somewhere that documents your build?

There are lots of cheap cores on Craigslist, but being a Mopar noob I have no clue which ones to covet and which to avoid. Probably better off leaving it to a pro in my case...

[Challenger340]

The DANA 60 is a much tougher diffy than an 8 3/4 when it comes to "hammering" on it with a 4 spd, especially once you get traction.
Given the expenditure you are looking at just to beef up the 8 3/4 ?
IMO,
BEST money spent, would be to just spring for the DANA 60 (and cheaper in the long run).       

Can't beat Dr. Diff, great guy to deal with 

[c00nhunterjoe]

Depends on your personal abilities, capabilities, and or local shops. I built my own bullet proof dana for under a grand less brakes.

Is there by chance a thread buried somewhere that documents your build?

There are lots of cheap cores on Craigslist, but being a Mopar noob I have no clue which ones to covet and which to avoid. Probably better off leaving it to a pro in my case...

I didnt do a topic on it. But the basics were a dana 60 full floating rear out of an old chevy truck. 25 bucks at tbe junk yard. Cut the ends off, weld on mopar ends- 80 bucks through dr diff if i recall. Strange 35 spline full spool- 175 bucks from summit.  I had gears but they are between 2 a d 300 for a pro set, bearing and shim kits are about 130 bucks. Axles and bearings new from dr diff are 300. Covers are anywhere from 20 to 200 depending on a stock or up to an aluminum girdle, i just put a 25 dollar chrome one on mine. I think im only missing gear oil in there? Oh, the yoke from the 8.75 swaps over or if you step up to a 1350 joint they are around 75 or 80 bucks new. So if you have the tools and abilities to do it yourself, you can build one for under a grand, shop prices will vary if you pay someone to do it.

Edit- i did do a writeup- http://www.dodgecharger.com/forum/index.php/topic,113690.0.html

[DAY CLONA]

Go with a DANA 60 don't waste time and money on the 8 3/4 rear esp with a 4 spd, contact www.doctordiff.com reputable company to deal with, the owner Cass is very knowledgeable and will steer you in making the right choice

How much do you believe I will expend?

You'll start out at $2150 USD, it depends what options you want to add, or changes made, talk to Cass/Dr Diff, the $1600 you were going to waste on the 8 3/4 is best applied towards the Dana 60, I speak from experience, I've destroyed a lot of 8 3/4 axles behind a manual transmission, Dana is the only thing that will take the abuse

Mike

[Scaregrabber]

Yup: Dana 60. Just call the Doc. Your current brakes will bolt right on to the new Dana 60 if you're pinching pennies.

Sheldon

[Kern Dog]

Are you here in the United States? You can find a truck Dana 60 in a junkyard and collect the parts to convert it to a car type unit. A good machine shop or axle shop can weld on the correct axle housing ends to allow you to use car style axle shafts and brakes. You can get this done for $1200 by being careful with your money. The down side is that YOU are the one doing all of the running around, collecting parts. etc.

[c00nhunterjoe]

. The down side is that YOU are the one doing all of the running around, collecting parts. etc.

Isnt that one of the best parts of this hobby? Lol 

[green69rt]

I really am no expert but I just put together a 8 3/4 about two years ago.  Existing 489 case, blasted and powder coated, original axles, Dr Diff 8 3/4 Suregrip with 3.91 gears.  Dr diff rear drum brake kit.  Assembled locally.  By the time all was done it was over $2000.   I could have had a Dana for that!

This site would help.  Call them to see what you can get.

http://www.strangeengineering.net/product/s60-rear-end-trac-lock-35-s-t-axles-leaf-spring-mounts.html/

[Midnight_Rider]

I didnt do a topic on it. But the basics were a dana 60 full floating rear out of an old chevy truck. 25 bucks at tbe junk yard. Cut the ends off, weld on mopar ends- 80 bucks through dr diff if i recall. Strange 35 spline full spool- 175 bucks from summit.  I had gears but they are between 2 a d 300 for a pro set, bearing and shim kits are about 130 bucks. Axles and bearings new from dr diff are 300. Covers are anywhere from 20 to 200 depending on a stock or up to an aluminum girdle, i just put a 25 dollar chrome one on mine. I think im only missing gear oil in there? Oh, the yoke from the 8.75 swaps over or if you step up to a 1350 joint they are around 75 or 80 bucks new. So if you have the tools and abilities to do it yourself, you can build one for under a grand, shop prices will vary if you pay someone to do it.

Edit- i did do a writeup- http://www.dodgecharger.com/forum/index.php/topic,113690.0.html

Thanks for taking the time to reply. Nice GL, btw!

I broke down the cost:


25 Dana from junkyard
80 Mopar axle tube ends
    differential
300 gears
130 bearing and shim kit
300 axles and bearings
25 rear cover
80 yoke
    gear oil
________________
940   
   
This is your total, approximately
   
   
   
200 Dana from junkyard or craigslist
80 Mopar axle tube ends
320 differential
300 gears
130 bearing and shim kit
300 axles and bearings
25 rear cover
80 yoke
    gear oil
________________
1435   

This is about what it would run me today, based on availability in my area.
   
Plus spring perches, any shipping and gas/time considerations. Add in paying a shop to do it and it gets up there pretty quick. Might still save a bit though.

Once again, thanks for the info.

[lucascosta21]

Thank you every one for you replies. I appreciate them.

I am not in US, then pick every part and bring them separatelly to Brazil can be a problem, but the difference of prices are tempting!

I will make contact with Dr Diff guys to get an offer.

When you say that someone broke the differencial, what exactly breaks? Because I can't undestand very well what is the difference between 741 x 742 x 489 and also why they are weaker than Dana 60.

Can anyone clarify this for me?

One more question: I have a rear axle from a 72 Charger with me, is it the same as the 68? Does it fit in my 68?

Thank you.

Lucas

[c00nhunterjoe]

If you have to import it, it may be better to just buy a complete rear because of those import taxes. Strange sells a complete brand new dana. Im not sure if dr diff does.

[Midnight_Rider]

Strange sells a complete brand new dana. Im not sure if dr diff does.

He does, looks to be the same Strange stuff:
http://www.doctordiff.com/strange-60.html

[Highbanked Hauler]

Hi guys,

My 68 has a 440ci and I swaping it auto trans for a 4-spd. Originally it came with a 318 and a 741 third member which I suppose has a long ratio (I didn't meet yet my car, so I didn't know the ratio exactly but I can imagine that is low due to the auto trans column) and, as I'm changing the transmission, I would like to improve also the rear end.

I want to let it with 3.73 or 3.91. I've been consulting guys from Mopar Madness and they suggested me do not expend in my 741, but swap it for a 742 or 489. They sent me an offer for a complete 742 kit with sure grip includded of $1600.

Now my question is: What is the best to do? Go on with this 742 kit or change everything for a Dana 60? How much I will expend with a Dana 60?

*In the future I intend to upgrade my carb for a six pack.


   You going to do any distance driving or is this a track car ?

Do you suggest any reliable place ou guy who works with Danas?

Thank you.

Lucas

[cdr]

Thank you every one for you replies. I appreciate them.

I am not in US, then pick every part and bring them separatelly to Brazil can be a problem, but the difference of prices are tempting!

I will make contact with Dr Diff guys to get an offer.

When you say that someone broke the differencial, what exactly breaks? Because I can't undestand very well what is the difference between 741 x 742 x 489 and also why they are weaker than Dana 60.

Can anyone clarify this for me?

One more question: I have a rear axle from a 72 Charger with me, is it the same as the 68? Does it fit in my 68?

Thank you.

Lucas

the 741.742. 489, are all comprable , if you were to break one you likely would break the other.

[lucascosta21]

If you have to import it, it may be better to just buy a complete rear because of those import taxes. Strange sells a complete brand new dana. Im not sure if dr diff does.

They do. I've just received a quote from Cass: $2590 complete (using my original brakes). Look:

New bolt-in S-60/Dana 60 assembly built with 35 spline axles, choice of ratio, 1350 yoke and HD S-Trac differential $2590.

Freight cost TBD.

What do they mean with freight "TBD"?

[green69rt]

If you have to import it, it may be better to just buy a complete rear because of those import taxes. Strange sells a complete brand new dana. Im not sure if dr diff does.

They do. I've just received a quote from Cass: $2590 complete (using my original brakes). Look:

New bolt-in S-60/Dana 60 assembly built with 35 spline axles, choice of ratio, 1350 yoke and HD S-Trac differential $2590.

Freight cost TBD.

What do they mean with freight "TBD"?

"To Be Determined"

[alfaitalia]

Thank you every one for you replies. I appreciate them.

I am not in US, then pick every part and bring them separatelly to Brazil can be a problem, but the difference of prices are tempting!

I will make contact with Dr Diff guys to get an offer.

When you say that someone broke the differencial, what exactly breaks? Because I can't undestand very well what is the difference between 741 x 742 x 489 and also why they are weaker than Dana 60.

Can anyone clarify this for me?

One more question: I have a rear axle from a 72 Charger with me, is it the same as the 68? Does it fit in my 68?

Thank you.

Lucas

the 741.742. 489, are all comprable , if you were to break one you likely would break the other.

There are significant differences in strength....I could not be bothered to write loads this late...so stole this from an axle website;


''741' Casting - 1 3/8" (1.375" Small Stem Pinion.
Carrier casting numbers were 1820657 (1957-1964) and 2070741 (1964-1972). This unit was usually used in low weight/medium horsepower and high weight/low horsepower applications. Although it is the weakest of the 8.75" units, it is still a stout unit, and is stronger than the Spicer-built Chrysler 8.25" rear. The 1 3/8" pinion is also larger than the pinion in the Ford 9" rear.
''742' Casting - 1 3/4" (1.75" Large Stem Pinion.Carrier casting numbers were 1634985 (1957-1964) and 2070742 (~1961-1969). This assembly was replaced by a phase-in of the 1-7/8" pinion '489' casting starting in the 1969 model year. This assembly was typically used in high weight/medium horsepower applications through high weight/high horsepower applications. Although not generally considered to be stronger then the '489' carrier, the '742' carrier is extremely stout, and is favored by many Mopar enthusiasts because they are easier to set up. Noted Mopar enthusiast John Kunkel mentioned that the biggest advantage of the 742 carrier is that it has the largest rear pinion bearing of all the 8 3/4" carriers. The larger bearing helps to prevent pinion deflection better under a load than the others.
'489' Casting - 1-7/8" (1.875" Tapered Stem Pinion Carrier casting numbers were 2881488 or 2881489 (1969-1974). This assembly was introduced in 1969 and was phased-in to relace the 1-3/4" pinion '742' unit through 1970. Note:  the 1-3/4" pinion also appeared in some '489' carriers during this period.  By 1973, the '489' was the only unit available in passenger car applications, and was typically used in high weight/medium horsepower applications through high weight/high horsepower applications.  This carrier is considered to be the strongest by some Mopar enthusiasts.  Because it requires a crush sleeve to set bearing preload, some Mopar enthusiasts prefer the '742' casting.  This is not really an issue now because there are now parts available to eliminate the crush sleeve.

[cdr]

Thank you every one for you replies. I appreciate them.

I am not in US, then pick every part and bring them separatelly to Brazil can be a problem, but the difference of prices are tempting!

I will make contact with Dr Diff guys to get an offer.

When you say that someone broke the differencial, what exactly breaks? Because I can't undestand very well what is the difference between 741 x 742 x 489 and also why they are weaker than Dana 60.

Can anyone clarify this for me?

One more question: I have a rear axle from a 72 Charger with me, is it the same as the 68? Does it fit in my 68?

Thank you.

Lucas

the 741.742. 489, are all comprable , if you were to break one you likely would break the other.

There are significant differences in strength....I could not be bothered to write loads this late...so stole this from an axle website;


''741' Casting - 1 3/8" (1.375" Small Stem Pinion.
Carrier casting numbers were 1820657 (1957-1964) and 2070741 (1964-1972). This unit was usually used in low weight/medium horsepower and high weight/low horsepower applications. Although it is the weakest of the 8.75" units, it is still a stout unit, and is stronger than the Spicer-built Chrysler 8.25" rear. The 1 3/8" pinion is also larger than the pinion in the Ford 9" rear.
''742' Casting - 1 3/4" (1.75" Large Stem Pinion.Carrier casting numbers were 1634985 (1957-1964) and 2070742 (~1961-1969). This assembly was replaced by a phase-in of the 1-7/8" pinion '489' casting starting in the 1969 model year. This assembly was typically used in high weight/medium horsepower applications through high weight/high horsepower applications. Although not generally considered to be stronger then the '489' carrier, the '742' carrier is extremely stout, and is favored by many Mopar enthusiasts because they are easier to set up. Noted Mopar enthusiast John Kunkel mentioned that the biggest advantage of the 742 carrier is that it has the largest rear pinion bearing of all the 8 3/4" carriers. The larger bearing helps to prevent pinion deflection better under a load than the others.
'489' Casting - 1-7/8" (1.875" Tapered Stem Pinion Carrier casting numbers were 2881488 or 2881489 (1969-1974). This assembly was introduced in 1969 and was phased-in to relace the 1-3/4" pinion '742' unit through 1970. Note:  the 1-3/4" pinion also appeared in some '489' carriers during this period.  By 1973, the '489' was the only unit available in passenger car applications, and was typically used in high weight/medium horsepower applications through high weight/high horsepower applications.  This carrier is considered to be the strongest by some Mopar enthusiasts.  Because it requires a crush sleeve to set bearing preload, some Mopar enthusiasts prefer the '742' casting.  This is not really an issue now because there are now parts available to eliminate the crush sleeve.

the smaller stem is not what USUALLY breaks, the ring gear teeth is what gives up. gear deflection !!

[1974dodgecharger]

just get the DANA and be done with it.....

[lucascosta21]

the smaller stem is not what USUALLY breaks, the ring gear teeth is what gives up. gear deflection !!
[/quote]

My doubt remains. If I look for a manufacturer which build a ring and pinion with a special forged steel (more resistant material), for example. Would my 741 support my 440 4-spd?

[c00nhunterjoe]

the smaller stem is not what USUALLY breaks, the ring gear teeth is what gives up. gear deflection !!

My doubt remains. If I look for a manufacturer which build a ring and pinion with a special forged steel (more resistant material), for example. Would my 741 support my 440 4-spd?


[/quote]

Yes, if it isnt run on sticky tires....

[lucascosta21]

the smaller stem is not what USUALLY breaks, the ring gear teeth is what gives up. gear deflection !!

My doubt remains. If I look for a manufacturer which build a ring and pinion with a special forged steel (more resistant material), for example. Would my 741 support my 440 4-spd?

Yes, if it isnt run on sticky tires....
[/quote]

It's a 275x60 in the rear and 255 in the front

[cdr]

go ahead & build the 83/4 it will be just fine,    

[Kern Dog]

It is not just a matter of the size of the tire but also the tread compound.
If you plan to beat on the car, why not default to what the factory did? If you leave the line easy and just hammer on it from a roll, you will probably be fine with the 8 3/4" setup.

[c00nhunterjoe]

It is not just a matter of the size of the tire but also the tread compound.
If you plan to beat on the car, why not default to what the factory did? If you leave the line easy and just hammer on it from a roll, you will probably be fine with the 8 3/4" setup.

Yup, and then whats the point of a 4 speed if you are going to baby it?