[PHILLIP LOPRESTI]

I'm Talking About Rear Axles Guys... I Always See 9" Ford Rear Ends For Sale For Chevelles...are They Just As Good As Stock Gm Or What? Thanks Ahead Of Time For Any Info. Phil

 

[Bob West]

Re: IS 9 inches O.K.?

I don't think they are any stronger than a well built 12 bolt, the advantage they have is ease of changing gears. I think it might slightly more power to turn a 9" because of pinion gear location in relation to the ring gear.

 

[EMcIllece]

Re: IS 9 inches O.K.?

Mr. Bob is correct, actually a 12 bolt is a better rear end, but the 9" is kinda the standard rear end for racing.

 

[sschevellefan]

Re: IS 9 inches O.K.?

They are easier to get parts for to as far as 3rd members and gears. Fitting them in a chevelle with stock brackets can be a pain unless you buy the housing already done. My buddy went with a 9" in his 67 to replace the 10 bolt only because it was cheaper for him then trying to find a early 12 bolt then buy axles, gears, ect.

 

[wanarace]

Re: IS 9 inches O.K.?

The biggest advantages are the drop out center section, as mentioned, and bolt in axles. At certain power levels c clips are just not gonna cut it. You can get the eliminator kits, but they tend to leak. Some guys will put 9" ends on the 12 bolt and use special axles. For all that work I would just go with a 9".

Steve

 

[Schurkey]

Re: IS 9 inches O.K.?

And, there's a bazillion gear ratios available for the 9".

As for me, I'd walk rather than install a Ford part in my GM car. (at least a visible, major component like an axle...)

 

[Harold Sutton]

Re: IS 9 inches O.K.?

And, there's a bazillion gear ratios available for the 9".

As for me, I'd walk rather than install a Ford part in my GM car. (at least a visible, major component like an axle...)

This is short sighted. Think before you make a bad decision. The nine inch Ford is far stronger in several critical areas than the twelve bolt. The main advantage is the pinion is supported on both ends and doesnt spread under extreme load. Also there are literally dozens of different gear ratios for the Ford. One can set up several different rear end center sections and change out ratios in an hour or less if you have the wrong gear for a race. The twelve bolt has many pieces that aren't up to the pounding that big tires and tranny brakes give you. Some of the better nine inch units have a load bolt to further strenghten the pinion. The primary disadvantage is they take a little more power to turn than a twelve bolt. My son has had a "bolt in" Currie 9 inch in his very high powered Chevelle for about 10 years and has had very good luck with it. When something works i have to give it a thumbs up, no matter who designed it. Actually not even the 31 spline axles that came in the rear end have ever shown any signs of fatigue. The only part that did finally crack was the "non nodular" center section which he replaced with a nodular piece last year. This was in a 3580 pound car that was running high eights at the time. They also have the advantage of having the tabs for the upper control arms located higher which moves the instant center rearward and helps the car bite better.

 

[ak69]

I am running a Currie built Ford 9" in my 69. It's a nice piece for sure. All brackets spot on for a bolt in application. I have flogged the 31 spline axels and the locker, no issues what so ever.

 

[sobever066]

I bought a chris alston bolt on fab 9 for my 66 chevelle. I blew my 12 bolt up. I get compliments about it all the time.

 

[forcd ind]

if you use a 9", have them put 12 bolt style ends on it, and you can use your stock brakes(the backing plate needs to be bored out a little) or upgrade to the larger brake kit from mp

 

[HemiTCoupe]

Most 9" axles are cut and spline, were chevy thins down before the spline.

Pat

 

[sschevellefan]

if you use a 9", have them put 12 bolt style ends on it, and you can use your stock brakes(the backing plate needs to be bored out a little) or upgrade to the larger brake kit from mp

If you set it up with 12 bolt ends, how would you retain the axle? The 9" uses a plate and the 12 bolts don`t.

 

[Malibu Vette]

I too have a currie 9" with a spool in my car. No problems and looks good. I am thinking of adding Art Morrison upper mounts and modifying my Edelbrock upper arms to give me adjustable IC on the 9".

 

[Whittaker]

The brake backing plates like said get bored or ground out in my case slightly and then the same bolts that held the backing plates on now will hold the retaining axle plate on. I have the Moser rear in my car. I couldn't find a 64-67 housing for anything. I have a 68-72 12 bolt in my wagon but it is wider and the max tires on stock rims are 255/60 15". With the Ford 9" and stock width I bet I can get a 295 or more in there. I have 275s now on my 2 door.

I'm thinking of going to a 3.89 instead of the 3.50 and it a much easier swap as mentioned before.

 

[PHILLIP LOPRESTI]

Thank You Again Everyone For Clarifing This...i'm Very Glad That I Joined Such A Great Tech Group!!! Phil

 

[joespanova]

Anyone who says the twelve bolt is as strong as the 9 inch simply hasn't built both. The nine inch Ford ring gear in addition to being larger works with a pinion that is supported by a third bearing on its nose where the twelve bolt does not........in order of difficulty to assemble , most difficult.... Dana then twelve bolt and finally the easiest....the nine inch Ford. The only reason to use the twelve bolt would be for the last bit of ET needed to run heads up or to bomb some national record if the rules permit the change....ex. Hemi Cuda SS car may be found with the twelve bolt for the reasons someone stated ....the relationship between the helical contact points and distance from c/L is most efficient with the twelve bolt. Production housings ( for the 9 inch) are readily available and back braced with the face plates reinforced are extremely strong..........I speak from experience

 

[Sandy]

Does anyone make a brake drum to fit the ford 9 inch when using chevy bolt pattern axles ?

My brake drums are the ford ones and are drilled to accept the chevy pattern. Works but not the neatest setup and when the drums are too thin then back to drilling another set.

 

[Whittaker]

There are a lot of cars that could be donors for brakes. Or step up to rear discs while your at it. Stainless Steel brakes had a 11" drums for the rear with Chevy patterns. You would still probably have to grind the centers out a bit.