i noticed some companies are offering ford 9" housings with olds ends. Why? These come with rolling chassis dragsters and altereds. i also noticed the same company offers 9" housings with ford ends----and this is for a chevy impala. (?) The same company also offers 9" housings with a totally custom end that apparently neither based on either the ford or olds/pontiac design, yet can accept the 3.15" overall diameter bearing. This is for camaro/firebird. Befuddled.
1) Could be, but in the case of the diggers and altereds, since everyone is (apparently) ford crazy over rear axles AND if you bought a dragster or altered you probably wouldn't have stock brakes lying around anyways. So why not just "go with the flow" and go ford brakes. Just my theory here, not saying i agree because i don't---the part about going with ford brakes. Apparently S+W race cars doesn't agree either. 2) If it's an impala, wouldn't you want to keep the 12 bolt brake setup?
When you're narrowing a rearend, you can weld just about any housing end on any tube. Most of the aftermarket housing end just butt wweld to the tube. So it wouldn't make any difference what the customer wanted, they can do it. Maybe that's what they are advertising. I'm sure there are housing ends that take 12 bolt Chevy brakes too. Larry T
Larry & I were both kidding when we said "could be". Back in the seventies and eighties, when everyone started switching over to ford rears, a LOT of older race cars had been built around olds rears. Being able to buy your 9" housing with olds ends simplified the swap, and saved money on parts. You will often see Mopar ends as another option. This is because from the mid sixties/early seventies, Mopar 8 3/4 rears were another popular choice in diggers and altereds.The practice of chassis builders offering Olds and Mopar ends has hung on since then. The reason we gave is the answer. You really spend a lot of time overthinking things, and it frequently sends you down the wrong road. Like on your post about building tiny ci small-blocks to get better mileage. Curiousity and a desire to think things through is a positive trait, one I have myself. But it has also led me down a few dead-ends in the past, and it causes me to overthink things. As I have gotten older, and more importantly, gained more experience by following a few of these dead end paths, I have become more pragmatic. When I started out in this thing, I was told the same thing I am telling you now, by some older, wiser, far more experienced racers. I'm not saying don't be curious, but what I am saying is, dont spend alot of time trying to re-invent the wheel. Just passing down some of the same advice that was given to me 35 some odd years ago.
i agree but: 1) Why the assumption from the vendor that if you were going to order a dragster or altered that you would want to use olds brakes? Yes, olds/pontiac rears were popular---about 45 years ago. But you would have olds brakes just lying around? (as if?) 2) Again, if you had a impala and were going to put in or replace a 12 bolt rear then wouldn't you already have chevy/gm brakes, not ford? While it may appear that i am "overthinking" this matter, i have specific reasons for be thorough.
Something to think about is that early 9's had narrow brake pads which were at times less favored and harder to get except in a cheap replacement vs Olds-Pontiac. The axle bearing from the large bearing 9 od is the same as Olds-Pontiac so it's a natural swap... even on an old Ford drag car. A 12 bolt even though it has it good points like lower drag has never been the rear to own unless you had a GM car-GM donor for your build. Plus to use GM ends you need to buy-make C-clip eliminator ends. Most racers don't put themselves through the hassle of "correct" and lack brand loyality beyond the engine and the badges on the body. This is much like asking why a modern strut can still be ordered with an Anglia spindle. The light spindle was a popular choice way back then for building drag axles, when the guys upgraded (guess what) they didn't what to buy new custom wheels and it became a staple. It's the way we did it, others followed and will continue to do so, simple as that.
with todays high traction tires. The shock on the rear axel's is transmitted more to the wheel bearing as the torque load goes thru the components to the tires...
I have always used Olds housing ends on any of my 3" housing tubes no matter what style rear end because it is a bigger axle bearing, that is what I was taught many years ago, and have always stuck with it even today. I was not thinking about having Olds brakes laying around, but buying Olds off set disc brake kits. I have put Olds ends on 12 bolts, 9" Fords, and back on Olds housings now. Now that I am building two different period cars, one will have an olds disc brake package, and the other just might have a drum brake set up, you just have to hunt for the stuff. But, I believe what was said earlier in this post, it was a money saver back in the 9" transition period.
I bought housing ends for a 9" from Strange with camaro bolt pattern, I had Camaro brakes lieing in the corner if I was buying housing ends anyway I figured I might as well have ends that matched my brakes. The bolt pattern wasn't only the same but it alos allowed for the difference in stand off on the Ford axles. It was plug 'n' play. Lots of fellas have brakes already and don't want to have to fiddle around making them fit.
The big Olds and the big Ford both take the same bearing, the only difference is the caliper bracket bolt pattern. Most brackets today are drilled both patterns so it won't matter which housing end you have. As already mentioned when upgrading from say a early olds to a Ford 9", a lot of fabricators would just cut the ends off their customers old housing and weld it on the new housing = no brake replacement needed. Having new ends available makes it much easier as most shops stock them new, and with the ends now having duel patterns. This was just a drag car deal but now it has migrated into street rods as well. Van
i guess what i'm REALLY trying to find out is how did the stock Olds/Pontiac rear and ford 9" end up with the same size(apparently) bearing? Coincidence? Or something else?
I really have no opinion to add, i do have pics though. I buddy gave me an older aftermarket 9" housing, i cut the billet steel Olds bearing ends off to use on my Halibrand quickchange, converting to solid axles instead of floaters. Why were they there instead of Ford ends?
They designed rearends to work with existing bearings, not design rearends and scratch built the bearings to fit the design. Lots of interchangable parts on big 3 cars. Larry T
So all the engineers, both at ford and BOP decided 'Let's use the 3.15" O.D. bearing for the axle because it already exists and suits our load requirements.' Is that really what happened? Is this similar to 9/16" and 5/8" already bolts being very common so they ended up on a particular engine.
Perhaps not applicable to this discussion but in many applications c-clip axle retention is frowned upon and common 'c-clip eliminator' conversions are not acceptable for other than straight-line applications ergo 9in ends/bearings/retainers are the standard in applications that dont require floaters.
A cost saving factor for the designers of the later axles. Also parts like axles often are made out of house by suppliers who supply several manufactures and using one bearing for several applications makes a lot of sense there.
The engineers use the same formulas to figure the load requirements, so why would it be suprising for them to end up with the same bearing? Do they engineer a different spark plug for every different engine? Ford, Chevrolet, and Chrysler all used basically the same Holley on some of their engines. Ford even used a Quadra-jet on some engines. Thermostats, front wheel bearings, headlight & taillight bulbs. Same principle. Larry T
I have the ford 9" for Olds/Pontiac and its a huge 31 spline axle. 3.50 bearing and its a locked with 3.08 gears. It looks like it could take 600hp but dont know about the highway gearing! Know someone who wants one? Ive been reading all about the specs here and want to say thanks. Figured it out.
The same question has been asked by many, including me. In the early 80's, when I built my FED, it came with an Olds/Pont rear end, an open carrier, and 4.10 gearing. It also had disc brakes that were basically shot, and to replace them would have cost some $$$. So, I went with drum brakes so I could get parts anywhere at any time. BUT, whoever welded the ends on the housing welded them on "upside down"; I had to re-drill the backing plates to fit, and that became my biggest question, why was that done? Never got an answer than made any sense. I am Butch/56sedandelivery.
I'm running that exact set up. This became popular before aftermarket axles were readily available. The Olds axle is larger diameter than the ford 31 spline and tapers gradually without the ford step in the axle. So find an Olds 88 from the mid 70's, cut off the axle ends, save the axles. Weld the axle ends on the 9 inch and respline the Olds axles to ford 31 spline, go with whatever bolt pattern you want the flange is huge. I ran mine hard for 5 years in a street strip car on slicks, the same rear is with the car and will come along for the next build. Now that aftermarket axles are readily available, olds delta 88 are hard to find, it doesn't make a lot of sense, but I think it's bad ass.
There is a axle offset difference (wheel flange to bearing flange) between Ford and Olds. Disc brake kits carry different hats for each brand
Olds Pontiac is same bearing size as big Ford as discussed. Why reinvent the wheel, a lot easier to mate brakes from those that are readily available than source obsolete / unobtainiam parts
Well turns out my ford 9" is actually a pontiac rearend with a series 2 posi unit. Why does it look so much like a ford 9"? Any info. Getting confused.
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