how much power can a 8 1/4 take?

[BudW]

I am interested - but have a feeling Ed Dorcey will be closer.

 

[brotherGood]

Kettering ohio

 

[1980volare]

Holy shit. I've been off for this site for a while, and it seems people have become pretty stupid.


8.25 are junk. They break behind 4.0 jeeps. I've broken 2 behind a stock 318.


8.75 are better, but way more expensive, and absolutely NOWHERE near as strong as 9" ford.



Dana 60 are heavy, consume less power then a 9" or 8.75


Ford 8.8 is another good swap but will require some fab work.




That being said l. I'm selling my whole 8.75 if someone is interested. It can come in many different ways. If someone is interested email me at sport3519@aol.com



I can also do custom length dana 60s built to spec. Or narrowed 8.75, or even 8.8

 

[MiradaMegacab]

The only cars that got the Dana 60 in any volume were the manual 440s and the Hemis. Automatic 440 Six Packs, and some Hemis actually got 8 3/4" rears. Although the autmatic cars don't shock the rear end like the manual transmission cars, I would describe them as quite serious nonetheless. You may not, that is your opinion. I do, and think that most people do.

Never said using a blower and an 8 1/4" is economical. Did say using an 8 3/4" and a blower would work. Probably more expensive than a Ford 9". But I do believe just as strong as a Ford 9". I also believe that just throwing in a lowest common denominator solution is not really always the best choice. How does the aftermarket for the 8 3/4" stay healthy if everybody jumps to the Ford 9" anytime they want a stronger rear end? Or everytime somebody wants a hotter engine, they get a small block Chevy? The only reason that a small block Chevy has the aftermarket that it does is due to the >50 Million Chevy small blocks that there are out there. Using Chevy parts in a Mopar is a big no-no for me. They will work, but when the Mopar equivalent is just as good, at a non-major cost increase, pretty much puts me with the Mopar parts.

Sorry if my outburst was idiotic in your opinion. Point was, as idiotic as you may think it is, is that the Mopar aftermarket will only continue to exist if we support it. There is nothing superior about a Ford 9" over a Mopar 8 3/4". Yes, it has one additional bearing. The 8 3/4" has a thicker case. Depending on the failure mode, it may be better to have one vs. the other, but there is no clear technical superiority for the Ford 9" over the 8 3/4".

My statements are not theory. We are on an FMJ body message board. We are already out in the cold, not only with the average street machine crowd and the aftermarket, but even with the Mopar crowd in most cases. If you want to save money, if that is the over-riding concern, go with a more popular platform. If you want to stick with the cars on this board, you are going to pay more money, and parts are not going to be easy to come by. And by extension, an 8 3/4" may be more expensive than a Ford 9"; but depending on the deal at the time, maybe it won't be. Ford 9" rears are getting expensive, too. Aftermarket parts are cheaper for the Ford 9", but not night and day different (i.e. Ford 9"parts are not 10X cheaper than 8 3/4" parts).

 

[kkritsilas]

Yes, keep up with the name calling.

Whenever you finish being a 12 year old, you may want to read this:

Ford 9 inch or Mopar 8 3/4?

I am not the only person who thinks the 8 3/4" is stronger. And, if you had spent more time researching, you would have known that the highly vaunted rear pinion support is not considered an advantage by many, because the support for the rear pinion bearing is a weak point.

But hey, you just keep name calling.

 

[Jack Meoff]

Okay okay enough..........
People are offering their opinions here based on experience. There are no ultimate concrete answers to anything and going to the wall saying there are is bullshit.

The idea here is to offer opinions based on what people have used and has worked for them in a real world situation. NOT to quote the shit out of every piece of literature you can find and call it the bible.

If you've been on the track and dealt with these problems offer your answers and let the OP make their choice based on what people have had success with. If you haven't but have information you've read or researched then offer it but don't take a shit on the table because someone has done things differently than some online article said you should. Offer your opinion and then step back. Let others give their input. There's no need or room on here for kindergarten bullshit.

 

[MiradaMegacab]

LOL.....

 

[1980volare]

Look, it's absolutely not a matter of opinion. It's absolutely a fact. if they 8.75 was so much better then 9", why do the fastest door cars on the planet use a 9"?


The factory 8.75 case is the weak point, even with a nodular case, or even the MP aluminum case is just a bandaid and will fail with power and stress. The case flexes with tourque, and will break the main cap, and sometimes pull the threaded boss from the actual case. Even with MW caps you're flirting with disaster if you're making alot of power.



How fast have you been with a 8.75 in a door car/ streetcar?



They work good in some applications, but once you start making some steam, you're going to shear some pinions, and split some cases. If it's still 30 spline, expect some broken axles and some messed up carriers.



All depends on how fast you want to go, I've had many rear ends, and if I was to do it over again I would end up with a D60 or 8.8.

 

[jamf]

For the average person an 8 3/4 is going to be perfectly fine. Quickly getting harder and more $ to find though.
I wouldn't waste my time with an 8 1/4 or an 8.8 ford.

The 9 inch is nice because it is easy to setup and has plenty of aftermarket stuff available including beefier center sections for cheap. I've found the factory ford third members rear pinion support to be weak and crack.

I ran a 3.23 8 3/4 for many years in my 440 4 speed Diplomat. Built an engine making a little more steam along with a clutch that doesn't slip and the 8 3/4 became the weak link. I've twisted splines, broke teeth off ring gears, and broke the cap off of the drivers side.

I just put a Dana in about a month ago. Wasn't any sense ruining any more of my good center sections I could use in other cars. For what it would cost beefing up the 8 3/4 it didn't cost much more to build the Dana.

 

[Ed Dorey]

That's a bit out of my way unfortunately.

Kettering ohio

 

[slant6billy]

I've been handicapping my right foot since putting the 8 1/4 back together. The 8 3/4 will be going in sometime this winter, along with 6 leaf springs. Got one more show- Veterans/ Marines Bday/ Toys for Tots for the season. So no massive burnout or crazy nonsense. In otherwords: I'm like a neutered dog with that limp right foot.

 

[jasperjacko]

It was you axle that failed right? Maybe all you need at your power level is better ones?