8 3/4 + Hp = ?

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USCG CHARGER

USCG CHARGER

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I have a 600+ hp SB stroker thats going in my dart and wondering how much my 8.75 A body housing and case can take before I have to upgrade to a Dana 60? Right now I have 4:10 gears in a 742 case sure grip.

I dont have a brace on the housing either... would that solve my main issue?
 
USCG CHARGER said:
I have a 600+ hp SB stroker thats going in my dart and wondering how much my 8.75 A body housing and case can take before I have to upgrade to a Dana 60? Right now I have 4:10 gears in a 742 case sure grip.

I dont have a brace on the housing either... would that solve my main issue?
Click to expand...

You might be pushing your luck, is it an auto or 4 speed and are you going to be running sticky tires.

Terry
 
727 manual vb, and yes I'll be running slicks as much as possible.
 
USCG CHARGER said:
727 manual vb, and yes I'll be running slicks as much as possible.
Click to expand...

I'd have to say, IMO, that if you aren't at the limit you'll be real close with the slicks and the torque of a stroker, maybe the switch to a Dana would be safer. If you're going to run the 8 3/4 make sure you've got a driveshaft loop which you probably already know. The main issue is the size of the pinion shaft and whether you'll twist the end off her. You could change out to the 489 pumpkin with the larger pinion and add to the safety zone.

Terry
 
I was with some racers last night and they discussed the 8.75s capability.
It seemed that the consensus was that with big horspower it wouldnt live behind a 4 speed, or an auto with a trans brake.
One of the guys took out his new 8.75 ring gear on the first pass. He has a (est) 600hp/600+trq W2 head stroked 408 on alcohol, 904 with transbrake.
 
you better put a dana in it or it will cost you a trans and rear i know last year i broke my rear drove the car off the track in to the trailer put my spare chunk in it and the next week the trans exploded on the starting line and allso it broke my foot to just for good measures so go dana dude .
 
With that much power i would'nt chance it using a 4-speed,with an auto who knows,with an auto and transbrake i'd consider moving up to a dana...biggest weakness with the 8 3/4's are the caps...
 
I run a 580 hp, 544lbs torque 416 with a 727 with a brake, i have well over 500 passes on my 8 3/4 410 gear with a spool, no back brace, with 12.5 wide slicks, my best 60 foot time 1.42 with s/s springs, a never had a rear end failure yet. also i run a small ujiont drivshaft. best time to date is 10.30@ 130 mph. every fall i pull it apart take it to my machine shop and magnaflux the gears, and change the oil. thats it.

000_0088.jpg
 
mine did last about 12 years with moser axles and spool and billet caps and a brace but but the trans will screw up if it breaks and put a sheild on you trans because breaking you foot is not fun
 
why dont more ppl just buy DAna's? I see them on craiglist all the time for cheap. Then they can just have them cut to fit.
 
len340 made a good point.
If you sell the 8.75 you can take the cash to put on the DANA.
If ya break the 8.75 you will still want the DANA but won't have the cash.
Hows your luck hold up? Mine aint so good. I'd do the DANA.
 
Rumble beat me to it. Aftermarket caps are a must.and a backbrace is a good idea.Ring gear trying to walk exerts a lot of force on caps that is why they are the first thing to fail.
 
If it hooks real good I think it will blow apart, now maybe with better axles, gear sets and hardened parts maybe, but I think you are in 60 range buddy!
 
A friend of mine had a similar set up in a 71 Dart. He went through several 8.75 rear ends before he finally gave up and went to a Ford 9".

If it were me I would sell that 8.75 while it's still in once piece and get something better.
 
You know before coming to FABO I had never heard of problems with the 8 3/4 carrier bearing caps breaking but heh the rule of thumb of drive trains is that there is always a weak link. Over the years I've twisted the nose off of two 8 3/4 rears, I'm sure they were both 742's, once with a BB Roadrunner and once with a BB Charger. Coincidentally my last B Body was a 69 BB Bee with the 9 3/4 Dana and I tried several times to hurt it and it just sat back and laughed at me.

Terry :burnout:
 
len340 said:
you better put a dana in it or it will cost you a trans and rear i know last year i broke my rear drove the car off the track in to the trailer put my spare chunk in it and the next week the trans exploded on the starting line and allso it broke my foot to just for good measures so go dana dude .
Click to expand...
When you break anything behind the transmission; you also broke the sprag in the tranny- replace it
 
Food for thought. The factory put the 8.75 behind the Hemi in the LO23 coded Dart when using the automatic tranny. Behind the 4 speed in the same car they used the Dana 60. If using the 8.75 i would use nothing less than the 489 case and 1350 yokes.
 
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