will the 8.75 hold up ? Most likely, but IF I was going to go through all the work in your build, I'd just use a 10 bolt GM and be done with it.
SBC SWAP IN A 64 BARRACUDA?
- Thread starter Tony Cabler
- Start date
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BARF!!!!!
Hey, I'm trying to answer the OP's question and help out !Or a 12 bolt "Posi"
TT5.9mag
Two atmospheres are better than one
Wow a lot of you guys are really closed minded. Why do you care what he does to his car? I’ll tell you this, the last thing I ever care about is whether or not some *** hat at a car show will talk to me about my car. After all I didn’t build it for him.
Will it be better with a corvette frame, engine, trans? Who cares?
OP the 8-3/4 will live behind it just fine on drag radials. Up to the point of launching the car on a transbrake at 5000 rpm with 450hp. Foot brake and mild launches you’ll likely be just fine.
Will it be better with a corvette frame, engine, trans? Who cares?
OP the 8-3/4 will live behind it just fine on drag radials. Up to the point of launching the car on a transbrake at 5000 rpm with 450hp. Foot brake and mild launches you’ll likely be just fine.
Me too. What carrier is he planning on using for his powerful small block Chevy? Kink of a slap in the face asking about whether a 8 3/4 could hold up to that kind of horsepower. If the OP has a question whether it will hold up why not use a 12 bolt or a 9". Apparently the Mopar drive train isn't heavy built enough for a 350. WTF. I'm out.
Can you post pictures of the project, and how much progress you made so far ?
Why swap the worst V8 in and pull the best out? Then cut the torsion bars out for coil springs? In the end no one will want either.
Maybe the OP is just trying to make something DIFFERENT by using what he has at hand. The only question was about the durability of an 8.75 differential.
Who gives a **** what it is that he does with it. Yes, he did state the plan for his project, which probably half of the responses would have been asking about anyway. Too many purists stating opinions on something that is not their concern. That is what drives people away.
Who gives a **** what it is that he does with it. Yes, he did state the plan for his project, which probably half of the responses would have been asking about anyway. Too many purists stating opinions on something that is not their concern. That is what drives people away.
It is a disaster waiting to happen. In the end it will take too much time and money if it every gets completed, and on top of that, the end product will not be as good or valuable as fixing either.
TT5.9mag
Two atmospheres are better than one
In your opinion.
Maybe it will be his pride and joy.
Professor Fate
Push the button, Max...
Tried not to sound "closed minded", that's why I pointed out the differences that will need to be overcome- just because he may have the parts doesn't necessarily make it practical, and there may be more viable options out there.
In the end, as I said, it's his car. He can do whatever blows his skirt up. But mainly, he needs to be aware of the challenges he's facing and make sure they're realistically within his skill set.
And yes, the 8.75 can live just fine at those power levels. But I need to ask; if you're using an 8.75, what is the advantage of using the Corvette frame once you dispose of the IRS? Just curious.
TT5.9mag
Two atmospheres are better than one
Well I certainly can’t speak for the op but what if he’s building a gasser? Then it needs a full frame and a solid axle. Just a thought.
slickchick
pedal cars only
I don't think he's been back on since his initial post, He's just sittin back eatin his big bucket of } 
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Always a possibility that the OP does not have any of the Corvette driveline, only the motor.
The OP may have the gumption to finish his build, you never know. But, I've seen WAY too projects similar to his get pushed aside because of lack interest or the fun factor ran out. I, along with the greater majority say "yes" the 8 3/4 will hold up unless he unleashes hell on the drive train & it hooks up.
Professor Fate
Push the button, Max...
Then he needs a straight axle and early Hemi, not an EFI mousemotor!
pishta
I know I'm right....
note rear wheel wells.....Id start with the motor and trans in the Barracuda and go from there. It doesnt need the GM frame. When I had my STR-12'd 340 in my 65 Barracuda, I had 3 guys talking amongst themselves.." Why did he put a Chevy motor in this?" I just stood behind them and let them talk.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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You know that Chevy frame is a stinking heavy piece of metal right?
After you get that all put together and safe to drive, you might need a BB.
Or a lot more gear than 3.55s, cuz if I remember right, that Chevy trans has a 2.20 low, check it out. If I'm right, that makes your starter gear a paltry 7.81, which is not gonna play nice with a cammed up Chevy small block, at something like 3600 pounds.....
But I gotta say, that the 2.20 low, chevy box does have mighty nice tight splits;
2.20-1.64-1.28-1.00; splits of .745-.78-.78
But to get off the line with 29s, yur gonna need at least 4.88s for a street starter gear of 10.74
As for me, I like a (normalized to 24" tire) ratio of 9.75. With my 27s that comes to 27/24 x 9.75=10.97. I get that with 3.55s in the back and a 3.09 low in the trans; eat your hearts out, lol.
Ok suppose you don't understand this; I normalize every tire/gear combo, to a 24 " tire, which is a 1 foot radius, and so I can easily equate engine foot pounds to on the ground foot pounds. Of course nobody installs 24" tall rear tires, so all starter gears have to be similarly normalized.
So then, by actually trying nearly every ratio in the Mopar arsenal; by process of elimination, I have come to the conclusion that I like a normalized 9.75 starter gear.
With 27s and a 2.66 low, this maths to an actual rear gear of;
9.75 x27/24 divided by 2.66=4.12.
With 27s and a 3.09 low
9.75 x 27/24 divided by 3.09=3.55
With 29s and a 2.20 low
9.75 x 29/24 divided by 2.20=4.99
So then;
2.20 x 3.55 x 24/29= a normalized to 24" tire of, 6.46 starter gear; which is gonna suck supremely.
I've seen too many disasters similar to this, and I know the skill set required. In the end, the finished product is a worthless scrapped 1964 Barracuda, that does not do anything better than the original.
TT5.9mag
Two atmospheres are better than one
In most cases you are correct. But the bashing started without ever a mention of what his plans are. He’s not come back since posting so all of this may be mute anyway.
replicaracer43
Grumpy Old Man
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Most likely a chevy guy trolling is all
could even be a known member here sitting back and laughing.... or UTG getting even ...
Who knows, right?
Jeff Seighman
aka jeffnmo
HAH, UTG, wouldn't that be the ****!
He should just stuff a welded spider gear, 4.56 corporate 14 bolt GM 3/4 ton truck axle under that *****. He gonna need it with that 30 over 350 with double hump heads, three quarters race cam, pushing 700 horse.
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