8 3/4 vs Dana 60

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BoredandStroked

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I am wondering would a 8 3/4 be able to handle 700 horsepower? I have a Dana 60 out of a 79 Dodge D-200 Army Issued and was thinking about rebuilding it and installing it in my Dart. My main question is can a 8 3/4 handle 700 horsepower and will it be cheaper than rebuilding the Dana 60. I would need to change the axles for 5 lug and thinking about switching to some 3.54 gears (I think thats the number but it might be off) and of course a posi unit installed. I would do about the same with the 8 3/4... mid 3 gears and posi. Try and help my uneducated self in this please. Remember MOPAR OR NO CAR and thank you very much!
 
That all depends on what size tire you are going to use. If you are going to use a street tire or a slick no bigger that a 9 or 10" I would say traction will be your weakest link not your rearend.
 
that 8 3/4 will break as soon as you get the car to hook up. along with the driveshaft. i believe the 8 3/4 is rated about 550 hp... and i twisted my stock driveshaft at about 475 hp
an auto trans may strech the numbers a bit ... but i would build the dana and have a heavier tube shaft made ....the damage done to my car from that shaft failing was more than the cost of the shaft i had made afterwards....just my opinion.....good luck
 
It'll take more than 550 HP. It's more the shock load it can or can not take. 4spd cars are harder on it.
 
Yes, the 8 3/4 will take more. If any of u read Mopar Muscle Magazine there is a section on a 68 Charger built by Pure Vision. It had a 472 hemi pumping out 605 horsepower and had a 8 3/4 rear end and even better... it was a 4 speed.

I plan to run a 295/65/15 tire but I might go higher. I am more interested in road racing and handling thats the reason for the 3.54 gears. What would be the best tire for this application of horsepower and rear end. I am planning to run a 727 reverse manual valve body and some little TCI parts in it. I dont want a total tubbed out machine... mini tub will do fine of about 3 inches.

Thank you for your help and remember MOPAR OR NO CAR!
 
My Duster has 8 3/4 I have ran in the 10's with trans brake at 5000 rpm and no problem. I do have 35 spline axles and a spool. My dad back in '69 bought a 67 Hemi Charger 4-speed and took out the dana and swaped with 8 3/4(quick gear changes at the track) and was running the big racer brown cam and all the go fast stuff at the time, with 4.56 gears and launching @ 5000 rpm and never broke the rear end. In '92 we took out the 8 3/4 and put a dana back in(yes he still has the car) If any one has the book "Moter City Muscle" its the Gold 67 Charger that has the 2 page lay out. So no I would say the 8 3/4 will stand up to the task. Just my 2 cents
 
8/34 will be good up until a bit over 500hp "stock." Use some better bearing caps, axles and a back brace and they become damn near bulletproof. Plus it is lighter than the Dana. Like 340mopar said - tires, driveshaft, etc. will become the weakest link long before the 8 3/4 ever gives out.
 
you guys must have different 8 3/4 s than I have had in the past, We ran a four speed hemi 65 cornet ( b-body ) factory car back in 72 the dana wasnt in the car when we got it , we broke 3 rear ends the first summer, using only 10 " tires, not to mention twisted axles, that old hemi sure didnt make much over 500 hp. if my memory is correct it seems to me that car ran in the mid to hi 10s.
i do agree ,if you do use a back brace , heavy axles. and soft gear sets the 8 3/4 will take a great deal of abuse, altho the cost of all those mods will put you in a dana for about the same money, and we all agree the dana is stronger. starting from scratch why build a lesser unit if a better one is available? 700 hp was the # given .. you have to admit the dana will handle that much hp much easier than the 8 3/4.. like I said before this is just my opinion,

I just noticed in your latest post. you are planning on road racing your car. if that is the case then the 8 3/4 will most likely work for you , the stress on a road coarse is much less than a whole summer of drag strip action...
 
I'd be interested to know exactly what you broke? I'll bet it was axles and bearing caps, and I'l bet they were stock. Those parts can be replaced for FAR less than a Dana will set you back...
 
If your going to road race use 8-3/4, it is lighter for less unsprung weight than the dana 60. This will make you car handle better. Also DO NOT use the "green bearings" on your axles they are not designed to take very much side load. Use the stock style tapered bearings.
 
Not true. Ball (Green) bearings are fine for street use. Do a search to find the info debunking this myth. OBTW, tapered bearings rule out most aftermarket axles, so you're back to limiting HP to around 500 before the axles become the weak link.
 
There are a lot of guys here that would know better then me, but...the older Dana's in trucks weren't Dana 60's but where Dana 70's. As I remember the axle/axle bearings are different. Also, the overall length, obviously, is going to need be shortened to fit an A-body. It won't hurt my felings if I get corrected on this. No matter what you do, it's going to cost big $$$'s.
Mac
 
Ace said:
Not true. Ball (Green) bearings are fine for street use. Do a search to find the info debunking this myth. OBTW, tapered bearings rule out most aftermarket axles, so you're back to limiting HP to around 500 before the axles become the weak link.
Click to expand...
You are right "green bearings" are fine for the street but they are not to be used for heavy side loading applications (like road racing or circle track) or for trucks carrying heavy loads. Call Moser, Strange, whom ever they will tell you the same thing.
 
Green bearings were never designed with any specific application restrictions. The reason this myth got started was because the axles and bearing were mostly going into drag cars early on and the gearheads thought it must be something special just for them. Green makes the same bearings for all kinds of truck axles and there are millions of trucks on the road right now with axles riding on ball bearings.

Guess I better be careful taking any sharp turn on "the street" so as not to overload those bearings with any excessive "side loading", huh? I wonder if that side loading spec is something the NHTSA investigates at those accident scenes with green bearings and axles strewn all over the road. What is it measured in, pounds per ball-foot?
 
I am only going by what the axle manufacturers are telling me. I do not make the bearings or the axles. It is best to use the manufacturer recommendations, not some urban legend or backyard engineers opinion. By the way Moser makes a "circle track" axle and is uses, you guest it, a tapered bearing. This is not an ego thing so don't make it one. And you are not going to die if you lose an axle bearing. It will howl like hell before it completely dies.
 
I just called Randy's Ring & Pinion and they said the "green bearing" is not for heavy truck use or heavy side load use like road or circle track racing. They said it will wear out much quicker in that kind of application. The reason you have to use the "green bearing" on the Yukon axle is because it is shorter than the stock axle and is not long enough to reach the buttons in the center section with a standard tapered bearing. If the axle was the standard length you could have used the tapered bearing.
 
Oh yeah, Randy's Ring and pinion, probably selling the snap ring retainer Moser stuff talked about here - for more money than the bolt-on RP-400s, no doubt:

So here's the scoop:
The question is whether or not the RP400 bearing kit for Mopar 8-3/4" axles is suitable for street car applications. There has been a lot of discussion that since your catalog lists it under "Racing" that racing is the only application. Some have also said that the RP400 doesn't have enough lateral retention for street use. Others have said that they have several thousand miles of street use with the RP400s in their axles and have encountered no problem. Can you clear up the issue for me?

Dear XXXXXXXXX,

I received your question about the RP400. I'll try to answer this to the best of my ability. The original intent of the RP400 designed by the Green Bearing Company was meant as a replacement for the original taper bearings in the rear end of Chrysler / Mopar applications. It was made for street vehicles, as were all of Green's automotive bearings. Over time these products became favorites of custom axle manufacturers such as Moser Engineering, Strange Engineering and Mark Williams Enterprises. Green, being a job shop, manufactured a multitude of bearings for these outfits and started categorizing them as "Racing" bearings due to the fact that the products were becoming popular in that application.

There are a lot of these bearings on the road in both street applications as well as on track applications. As far as performance, all I can say is that these have been a staple in our product line with no revisions / issues for a long time. The experts on the performance of the product in various applications would be Moser or Strange. If you would like to contact them, you have to ask specifically for the RP400 with the fixed flange because there is a modified version (MO400) which was designed by request for Moser and has a slide over flange with a snap ring retainer.

You can visit www.moserengineering.com or call 260-726-6689 for more information.

Thank you for your interest in our products.

Best Regards,
Brian Graziadei

Bearing-Technologies LTD
 
NO that's not the question. I agreed with you that the "green style bearing" was fine for the street. Is not however RECOMMENDED for road race or circle track racing. BoredandStroked wants to go road racing. I never mentioned it was not suitable for the street. You are like a bad attorney you are try to put words into someones mouth.
 
OBTW, this is is not about egos, it is about getting the facts straight before you start giving people advice. So which is it, the RP400 or the MO400 you are talking about? I have a pet peeve about people talking BS when they are giving advice about stuff they know very little about. I'm no expert, but I can spot BS in a heartbeat. Sometimes people have to save up a long time to spend their hard earned dollars based on advice they might read here. Get it right.
 
Man, whats up, I agree that they is nothing wrong with them for the street. If i'm miss-informed then so are the companies that sell the bearings and the axles. The RP400 and the MO400 are the same bearing with the one exception, how the are attached, the MO400 has slip over flange and used a snap ring to hold it on the axle instead of being pressed on like the RP400. But to end this sillyness I will say you are right in every respect. Lets say for argument sake I am full of BS. At least I am above calling people names in an effort to make myself look better.
Now Good Day!
 
Just so we're straight: The RP400 was designed as a "replacement" for the Mopar tapered bearing. Assuming it was not designed to be inferior to the OEM bearing, it is just as good (probably better) and will last just as long (probably longer) in any application the car runs.

And I might add, you are the one who called me a "bad lawyer."
 
Everbody remember before you place an order with any axle manufacturer or supplier, like Moser, Strange, Randy's, etc ask ACE first because he knows and the rest are full of BS.
 
Oh, and I said you were like at bad attorney, that is a comparison. If I said you were a bad attorney now that would be name calling.
You said I was full of BS not "like" full of BS.

Since you seem to know some much about everything I'm suprised you didn't know the difference.
 
I though about it, that was a cheap shot... Sorry

Dude, were Mopar guys, were supposed to be on the same side.

Chuck
 
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