i am about to pull my last hair out. I want to put a 12 bolt in my 67 but i DO NOT want an original. I plan to narrow the rear to fit my mini tubbed car. i have been told that i do not want a truck 12 bolt and that some are really just 10 bolt parts in a 12 bolt case. how do i identify the correct one and what cars do they come in?
thanks
chris

If you have to modify it, get a F*RD 9 inch rear.

Yup a 9 inch would be the way to go if you are going to narrow it up. If money is no object you could always custom order a 12 bolt from Moser. Most 12 bolts lately are $200 and above no matter what car they came in. Camaro 12 bolts (and Novas) are substantially more money. Since you already have one Ford product I expect the 9 inch is something you are familiar with?

An Impala 12 bolt is the best one to modify for your type of project. I built one for a mini tubed '69 about 2 years ago. I also use them to build stock length Camaro and Nova rear ends. They are much cheaper than a Camaro or Chevelle 12 bolt and nobody cares if you cut one up. Let me know what you want to do with it and I can give you a list of parts that you need to build it.

Chris,

Don't listen to the FORD 9" non-sense, the 12-bolt is every bit as strong. I have seen many 9" center sections ripped out of the housing. The only drawback to a 12-bolt are the C-clips. The Moser idea is nice but pricey. You can cut a 12-bolt down to size, add new performance axels and 9" end caps and keep it Chevy!

Good luck!

Chris,

Don't listen to the FORD 9" non-sense, the 12-bolt is every bit as strong. I have seen many 9" center sections ripped out of the housing. The only drawback to a 12-bolt are the C-clips. The Moser idea is nice but pricey. You can cut a 12-bolt down to size, add new performance axels and 9" end caps and keep it Chevy!

Good luck!


i have to disagree with the strength. i live at the drag strip and 90% of the busted rears are 12 bolts. that is why they are hard to find . LOL. the pinon is just not supported well enough. but i do not intend to beat on this car like that. i have actually thought about putting my built 8.8 in my camaro and putting a 9" into my race car.

I vote for the 12-bolt, less torque to turn than a 9-inch.

Nine incher's are easier to service and set-up, but have more drag than a 12-bolt.

Now, you can get a 9-inch with a 12-bolt configured hogshead, but pricey.

I'd be interested in the offer Freddie has for the Impala 12-bolt to 1st Gen F-body conversion.......

ok, i just bought a 12 bolt out of a early 70's el camino SS for the grand total of $125. did i score a good deal?

Yea, that's a good deal, but I guess you are planning on cutting it up for the Camaro. Another Chevelle 12 bolt gone.

Yea, that's a good deal, but I guess you are planning on cutting it up for the Camaro. Another Chevelle 12 bolt gone.

well i will consider other options. i just was not going to pass this up. i like the idea of a 9" but i am going pro touring and need some nice brakes for it. right now i have 4 wheel disk brakes off of a LS1 camaro. i do like the idea of 9" ends to get rid of the c clips.

Sell the Elky rear on ebay and use the profits to buy a 9" :) What kinda gears does it have? I am looking for good 3.31 gears. I bought a set off of ebay but the Post Office bulk mail center shredded the box and lost the parts (no ins :(). I am calling them again today to see if they found the loose parts.

I wonder how you lose a ring and pinion gear. Probably fell out of the box and broke so they declared it lost.

I was on vacation when all this happened and the bulk mail place didn't send any notice until a month after he sent it. When I called today, They informed me they only keep loose stuff for 2 weeks then they send it to Atlanta mail recovery center to be auctioned. I wish they told me that sooner :( Atlanta has gotta be a big black hole of stuff, but the Philly mail guy said he would fax my paper work to Atlanta anyway (why didn't he just do this in the 1st place??) I have pretty much lost hope of getting them.

Do you know that the '68 and later Chevelle rear ends are 1 inch wider than the early Camaro rear ends? What is the code that is stamped on the right axle tube? If this is a '72 rear end with the CFC code on the axle tube I know a guy who is looking for one.

Do you know that the '68 and later Chevelle rear ends are 1 inch wider than the early Camaro rear ends? What is the code that is stamped on the right axle tube? If this is a '72 rear end with the CFC code on the axle tube I know a guy who is looking for one.

i will look in the morning. i want a 9", posi, 3.73 gears, about 5" narrower, with chevy axles!!!!

I can build that.

Okay, so you have seen failed 12-bolts. You didn't read my post correctly. The ring and pinion in a 12-bolt is still stronger than a 9". I can "tit for tat" you as I have seen the center sections of 9" rears torn from the housing more often than a 12-bolt C-clip failure. As previously mentioned, a 9" is less efficiant at transferring power to the ground.

A converted 12-bolt form a Chevelle rear would not be your best bet. You sound like you are wanting the dead strongest rear engd you can find and if that is the case step up to an aftermarket peice and sleep better at night.

Either way, a good rearend is like a good engine or transmission, they are NOT cheap!

Good luck in your quest for power and fun, Happy Hot Rodding!

i did not claim the ring and pinion were not as strong, i said the pinion was not supported as well.

aannnyy way it does not matter. i would be happy with either. i am running a modifed ls1 / t56 combo that will end up at about 400 rwhp and then a 200 shot of N2O on top of that.

i have actually thought about getting a 8.8 out of a ford truck. it has a 31 spline locker, it is very strong, nice brakes are easy to get, and the complete rear can be built for under $1000. that is not free but it is about half the price of a built 9" or 12 bolt. all you need to do is narrow it, weld the tubes, and order axles!!!

all you need to do is narrow it, weld the tubes, and order axles!!!
Hopefully, your tongue will be in the correct position so as not upset the squareness of the housing when welding.

This is why they make jigs.

If your heart is set on a 12 bolt I found one today that would work. It is an early Chevelle housing that someone has already cut the brackets off of. They welded some Camaro spring perches on it and messed them up. It is already too far gone to put back in a Chevelle, so it wouldn't hurt to cut it up some more. I really hate it because the early 12 bolt Chevelle housings are even harder to find.

Funny, all who are claiming the 12-bolt is as strong as the Ford 9", Chevy High Performance, and Car Craft have both done articles on the differences, and both have given the "nod" to the Ford 9"! I've copied part of their articles below, Also, the hp difference to turn the Ford vs. the chevy is only 2-3%, which tranlates to 10-15 hp on a 500 horse engine, which is certainly not enough to lose sleep over, as I've never seen anyone lose a drag 'cause the other guy had a whopping 10 hp more than he did. Anyway, here's the articles from the 2 mags:

Chevy High Performance:
Like the 12-bolt, the 9-inch pinion gear is shimmed to achieve the proper pinion depth with a small pinion shaft diameter of 1.313 inches. Another difference between the two rearends is that the 9-inch locates its pinion gear lower on the ring gear to improve tooth contact. This strengthens the rearend assembly but at the cost of approximately 2 to 3 percent loss of power to drive the gears compared to a 12-bolt. Of course, the sizes of the gears, cases, and bearings are relevant to strength, so you have to give the strength comparison to the 9-inch with its 0.125-inch larger ring-gear diameter and internal pinion support.

Another advantage to the 9-inch is that the axles are easier to install and remove. Ford designed the factory 28- and 31-spline axles to be removable by yanking four bolts per axle flange, which allows the axle to slide out. The axles have pressed-on bearings and retainer plates that bolt to the housing flanges. There are no C-clips inside the rearend holding them in place like on a 12-bolt. The plus here for the 9-inch is that if you break an axle inside the housing, the axle retainer will keep the axle in place. On a 12-bolt, breaking an axle means it slides right out of the housing, causing massive sheetmetal damage along the way. You can convert a 12-bolt to the 9-inch style of axle retention, but it requires a C-clip eliminator kit and modifications to the housing.

Ultimately, the selection of 9-inch vs. 12-bolt comes down to personal preference. If you are building a cruiser and want to keep everything GM, the 12-bolt is more than capable of taking the abuse. On the other hand, if you plan to flog your Bow Tie machine with slicks and lots of torque, it's hard to beat the 9-inch's strength and ease of service. Both are great pieces, so we'll let you decide.

Car Craft:
But if you're going Pro racing and do need the trick parts, aftermarket components based on the Ford 9-inch are available that can support anything up to and including a Top Fuel car. Nothing in 12-bolt territory even comes close. Aluminum or even magnesium third-members are available if you're concerned about the 12-bolt's weight advantage. If you want a rear that'll last virtually forever, the 9-inch Ford is your only choice.

Lots of good comments here. Just as a reminder to everyone, you can't always believe the magazine articles. Most of thier tech prowness is driven by advertisement and sponsors. This stands to reason as companies often give them parts to write articles about. I have many subscriptions and enjoy reading them all.

I have used many parts I have read about and have been sorely disappointed with either fit, finish or function. I build alot of motors, work on lots of muscle cars and trucks and I have learned that bolt on's are rarely that. The tricked out parts usually devoid your bank account and deliver nothing. And, the horsepower gains are not always what is printed or claimed.

Yes the 9" is easier to mount disc brakes. Alot of guys like using the Lincoln Versai rear end as it already comes with disc brakes and is fairly easy to install.

About the horsepower loss. 10 - 15 can make a differance. A classic case is the TH350 vs the TH400 battle. A TH350 is more efficiant at transferring power than the TH400 and the PowerGlide is even better. Every little bit helps.

Case in point. Some guys have lots of power and go slow. Some guys have less power and go fast. It is all in the Combo and Tuning.

This has been a good debate.

i have been thinking of putting a glide in my mustang. i really want to hit the 8's next season. i am running in the mid 9's and new engine is in the owrks. i need all the help i can get. having a steet legal 9 second car is great but i want an 8 second one!!!