Teach me about 9" rearends

Old 12-08-2007, 12:49 AM
  #11  
edvancedengines
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At one time if you looked on many of the Top Fuel cars you would find a 8 3/4 rear end. They were lighter and gave no trouble.

Fast forward to when Top Fuel cars strated getting traction and were hooking up. 8 3/4 quickly disappeared and were replaced with built 9 inch and with built Dana 60 's. Fast forward more and you find Those also began breaking and now they are using a huge pinion gear and a huge ring gear in a special made for them rear end.

All of my earlier experiences of negatives and positives with rear ends were all on clutch cars. The 8 3/4 was the weakest. Now possibly an 8 3/4 will handle an automatic car fine at a much higher power level with less initial torque hitting them or with a little tire speed.

Unless someone has recently started making them, you could not buy a 9310 Nickel gear set for the 8 3/4 and they were available for the 9 inch the Dana 60 and the 12 Bolt GM. That also is a brute strength issue.

Ed
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Old 12-08-2007, 03:03 AM
  #12  
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Default Re: Teach me about 9" rearends

Originally Posted by blaserman
I always have used 12 bolts but I hear 9" is stronger.
I also see 28-40 spline axles which is the best to have , how many splines
ok---LET'S GET THIS INFO---WHAT IS IT GOING IN AND IS IT STREET DRIVEN?---WHEN YOU CAN CHANGE THE GEAR RATIO QUICKLY THEN THE 9 "OR 8 3/4 REAR IS BY FAR THE BETTER SETUP PLUS IT IS ALOT MORE READILY AVAILABLE IN THE MARKET PLACE 8) -NO FORD OR CHRYSLER BIAS BEING SHOWN JUST BASIC FACTS[ NOT EVERYONE CAN SPEND 1000'S ON REAR END SETUPS--I HAVE HAD THE SAME 9" IN SEVERAL CARS OVER SEVERAL YEARS WITHOUT FAILURE[ I RUN A FACTORY WAR OR NODULAR CASE AND 31 SPLINE AXLES]---SORRY BUT I STILL LIKE THEM BETTER--YES I THINK THE DANA 60 AND THE FABBED REARS ARE FANTASTIC BUT THE ARE VERY, VERY EXPENSIVE FOR THE AVERAGE GUY---MY 2 CENTS WORTH --LIVELY

[BY THE WAY ALL OF MY CARS WERE 4 SPEED CARS] :lol:
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Old 03-22-2008, 11:54 AM
  #13  
blaserman
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Default Rear

I am finding a 12 bolt for a chevelle hard to find , and price is getting crazy. Most people want as much for a stock 12 bolt , as for a fabracated one on very close. I am leaning towards a 9" w/ 456 gears and a 30' tall tire. I am building a 632 10/1 motor . 400 turbo .I will drive on the street , but you know it has to go to the track and see what it will do.
I live near Auto fab and will use most parts from them . My friend is building a Chevelle and his rear set up is the same . I am letting him work his bugs out on his set up and I will have less work on mine.
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Old 03-22-2008, 02:00 PM
  #14  
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THAT IS SMART---LET HIM BE THE TROUBLE SHOOTER :lol: :lol: :lol:
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Old 03-22-2008, 08:44 PM
  #15  
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Default re; 9 inch fords

I*ve gota plain old 9-inch out of a 67 f-100 in my altered, no nodular case,a strange spool, 31 spline moser axles, new bearings throughout, and less than 900$ flange to flange. I buy parts at retail. My car is light. but I don*t understand 3000# race cars. I think the real beauty of the ford ,is you can change ratios quickly, they*re reasonable price wise, and any moron can build one. I am living PROOF! If you*re making TONS of torque, 4 digit horsepower, and a heavy car, then by all means go out and buy the biggest, baddest, toughest, rear end you can afford! you WILL pay for it. Please, don*t take any offense if you have a heavy car, as I meant none, we all build what we want.
P.S. What is a WAR case?
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Old 03-23-2008, 05:45 AM
  #16  
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Default rears

By the way this is a WHAT I CALL A STREET CAR, FULL BODY <FULL INTERIOR < RADIO ECT Not a race car.

What is the best spines more or less as in 31 or 35 splines.
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Old 03-23-2008, 07:19 AM
  #17  
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Default re; 9" fords

JMO, either a 12 bolt or a 9" will probably be fine for you on the street, But if you are going to WOOD IT, every time you leave a stop, you might want a dana 60. If I had a 632 cu. in. on the street, the state would take my license. :lol: No way I could resist the temptation. 35 splines are stronger than 31s but don*t know if they*ll fit in a factory carrier. Hey, keep it cheap, you*re going to buy lots of expensive gasoline!
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Old 03-23-2008, 06:41 PM
  #18  
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Dana 60 is the way to go. I have a ton of money in my 9" that is in my 69
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Old 05-10-2008, 04:35 PM
  #19  
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Default ford

Ford nine inch is the only way to go, stock or not!
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Old 05-11-2008, 12:04 PM
  #20  
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Hp difference between a 9 and a 12 is minimal.Like 3%,is what Strange claims,but a 9 will probably be lighter.But who cares about 10-15 lbs of rear end weight on a "street" car?Everyone claims a 9 is real strong,and I have one in my car cause my buddy gave it to me and it was already narrowed to what I needed.Used to run a 8.5 10 bolt with street gears and stock 28 spline axles.Drove it on the street for about 7-8 years like that,then took it to the track for about 100 or so 1/8 mile passes.Car is 3400 lbs(don't get me started,Earl )and has about 625+ HP.Never a problem with the "puny" 10 bolt.I'm not impressed with the 9,to be honest.I know you can swap gears fairly quick(no quicker unless you can afford a whole nother pumpkin) and they do hold up,but they seem thin to me.You can't brace the spool bearing in them like you can a 12 or Dana,no way to get to them.Pinion stem seems kinda small(10 bolt and D60 has same dia. stem,10 bolt has one extra spline)only thing I think they really got going for them is the bearing support for the rear of the pinion(next to the ring gear).Bearings are smaller than what was in my 10 bolt and bearins cap are smaller,too.Plus they look like thay are cast from some pretty cheesy 3rd world junk,real poriuos(think I spelt that wrong ops: )I honestly believe stock for stock that my 10 bolt was a far better rear than my 9".12 bolt will be even stronger.Had it to do over,I'd definitely go Dana.JMO
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