Thread: 10 bolt chevy rear end question

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I have a 72 Nova I just baught on this site and the guy said the rear end is a Chevy 10 bolt 4:56 built. Thats all I have, I have not opened it up yet but my Chevy truck 1989 has a 10 bolt under it and looking at the 2, the one under my car the pumpkin is twice as big as the one under my truck. Is there different 10 bolts how do I find info on the one I have I am scared my new 550 to 600 Hp 427 is going to rip it out from under the car. Are there casting numbers? or any way I can dertermin just what i have

after the 600 hp throws the pieces all over the track, replace with a Ford nine inch

That accaully made me giggle Thanks, My problem is my budget i just had to pu ove 4 grand into the engine I bought the car and was screwed on the deal it is costing me over 4 grand just to get the engine to the level were the person said it was at. I am probably goign to have to run it until I tear it up. I am just not sure exacly what I have, Is it possible to have a 10 bolt cover or housing and 12 bolt internals??

Creativity with the budget is the sign of a real hot rodder. If we all had huge big buckets of money, this hobby could get real boring, real fast. That’s not to say money shouldn’t be spent where it’s needed, but the 10 bolt rear end in your Nova might be okay. Note that Dave Henninger raced a 3,100-pound ‘71 Camaro in the NMCA’s Super Street class and consistently ran 8.70s at 150 mph with a 10-bolt rearend. As such, your 10 bolt might be just fine for the HP you're looking at.

The tern "n-bolt", when referencing the rearend, refers to the number of bolts retaining the ring gear to the carrier inside the differential. Typically this number corresponds to the number of bolts holding the differential cover, so you can usually tell whether you have a "10-bolt" or "12-bolt" rear from the number of bolts on the outside of the casing.

The best 10 bolt (from the factory) is an 8.5-inch from the ‘70-‘81 Camaros. Except for some one-off or special order cars, Chevy quit installing the 12-bolt in 1972. The 12-bolt is certainly a good rearend however; it measures 8.875 inches, or .375 inches larger than the “big” 10-bolt. There are several “small” 10-bolt rear ends as well (most notable the 8.2 inch). The good news is that Chevy used the 8.5-inch in 72-75 Novas. So, if your carrier is the stock one, that 4.56 is probably built on an 8.5-inch ring gear. The only way to be certain is to open it up.

I would recommend the use of a girdle (see below). They cost $150 - 175 from Summit or Jegs or probably a local go fast parts store. A “C-clip” eliminator is another $150 bucks. High performance axles can run another $250 - 300. Add new fluid and gasket you’re in about $650 - 700. If the 4.56 installation was done correctly, all of this may have been done.

A Ford 9 inch is a great upgrade. The best “nine-inchers” will have an "N" cast into the front of the case, between the webs, indicating it is made of nodular iron, as opposed to slightly weaker regular iron. They can be upwards to $2,500 new and $1,200 – 1,500 "used". You may have to add brakes and some plumbing parts that could be another $600 – 1,000.

I certainly hope this helps and that you're not too discouraged with a bad experience. I wish I had a buck for every "rebuilt" carb or trannie that I've ended up completely re-doing. Remember that "the only thing that's the end of the world is - the end of the world!" This isn't it!

Good Luck and Happy New Year,
Glenn

yes the gear it self is as good or better then a 12 the tubes on ether the 12 or the 10 can twist but with all the stuff glenn said it could hold up i have seen it done but i just went 9inch myself the N case is nice you can get way with a stock case and small pin bearing suport if you not going nuts as long as it is set up right i never have one blow the case up but when you start making big power it will wear the gear out fast .the stock N case is nice there is better . i never used a crush sleeve on all the fords i did i allways used a shim the cases that i like the best in iron is the Hot rod wheel case HRW better then others out there that i have set up

This is great,, I just got another call from my machinest and he told me that the aluminum heads I bought are a differant configuration from the iron heads I had, and it looks like with the longer valves etc I have to purchase a new set of pushrods I am going over there after work and if I have tme I will pop the cover and get some pictures of the ring gear and what not to post on here so mabey you guys can help me tell if I have bad or good set up.

thanks again esp for the pictures and suggestions

Originally Posted by chpseat987

This is great,, I just got another call from my machinest and he told me that the aluminum heads I bought are a differant configuration from the iron heads I had, and it looks like with the longer valves etc I have to purchase a new set of pushrods I am going over there after work and if I have tme I will pop the cover and get some pictures of the ring gear and what not to post on here so mabey you guys can help me tell if I have bad or good set up.

thanks again esp for the pictures and suggestions

get a size on push rods i maybe can help you out i have some smith brother push rods if needed

Thanks Pat I will, After getting home from the machine shop yesterday and the questions and help i got about my rear end, i decided to pull the cover off, and I was pissed.. the pinion gear clim's up the ring gear before it moves it around its sloppy, there are heavy scars on both ring and pinion and more scars on the spider gears and the center pin looks like it was hand ground with a die grinder dam neart in 1/2. So I am out looking in the sites today for a bolt in 12 bolt with 4:56's. Any suggestions?

Originally Posted by chpseat987

Thanks Pat I will, After getting home from the machine shop yesterday and the questions and help i got about my rear end, i decided to pull the cover off, and I was pissed.. the pinion gear clim's up the ring gear before it moves it around its sloppy, there are heavy scars on both ring and pinion and more scars on the spider gears and the center pin looks like it was hand ground with a die grinder dam neart in 1/2. So I am out looking in the sites today for a bolt in 12 bolt with 4:56's. Any suggestions?

put a 9 inch in it

Will it bolt in easy or will I have to make several modifications? I have ladder bars and stock spring mounts.

Moser, Currie, and a number of other companies make a 9" with all the correct brackets that will bolt right up to your Nova.

Bummer -

As mentioned above, there are several routes to a 9". Unless you're really attached to an "all GM" approach, you can get a rearend complete from Currie with a bullet proof 4.56 and Explorer disc brakes for $2,780. Ton-o-money, but it bolts right in and you will never have to address this component again this side of 800HP!

I'm a Chevy man - and reading through your saga makes my heart go out to you as it sounds like someone took you for a ride - but it sounds like the housing is trashed and there's nothing there to build from so the Ford 9" may be a good fit. To start from scratch, i.e., new carrier, tubes and spring mounts, with a 10 or 12 bolt will run a lot of money as well.

Good Luck,
Glenn

i have seen the nascar 9s pigs on e bay one would work save some money find a 80s pickup truck rear end . cut it down buy some new axles use the truck drums they are cheap for brake parts and stop your car very good