Olds/Pontiac Rear vs 9" Ford

George here's those pics. I'm posting so the rest of the world can know.
It would be nice if someone posted a pontiac/Olds and a genuine '57 Ford, comparison.

These would be what you would get if you snagged a '59 or '59 rear from a ford. The '57 doesn't have these dimples but they are hardly noticable when its all painted and nice and under your car.

Please excuse the rust I haven't gotten that far on this rear yet.

 

A guy could fill those with braze, and no-one would be the wiser.

 

Heat em and hammer 'em out. They are about 1/2" deep. Or you could braze bolts into them and make a saddle out of round bar and 2x1.4 plate. tell everyone it was like that when you pulled it form an old Willys gasser.

 

Also for the manual trans guys it really helps alot with the shock if you run a mopar or olds rubber injected driveline I have been using them for years.

 

I recommend using a 9" housing out of a Ford truck. The axle tubes are much larger and stronger than the ones for the cars. And like previously mentioned, you can get a center section that relocates the pinion gear and makes it easier to turn; thus, not losing horsepower. You can also buy different housing ends if you want to change them.

 

....... And they have about 50 different gear ratios to chose from...

 

The center section that relocates the pinion doesn't use Ford gears. I'm pretty sure it uses 12 bolt Chevy gears.
Larry T

 

And what is wrong with the chevy drop out rear end that came in it? They raced in about a billion chevys for about a million yeras? I have one in my Fuel car and it works fine.

 

I am a died in the wool 9" guy, I'd like to be a 10" guy. ooops sorry wrong site.

Anyway I run 9" Fords a lot. They are plentiful and cheap in the whole scheme of things. They do have some inherent weaknesses. The pinion and pinion support for one as well as the case itself. Even the nodular iron case will split if you really throw the meat to it. We are talking mega loads here to split the case but it is something that happens enough with dedicated race cars that there are plenty of aftermarket cases and pinion supports to overcome the problem.

Here is the deal on the beloved 9" Ford, it was not a 9" rear when everyone was running the Old/Poncho rear. It became a 9" rear in the '60s. All the Ford rearends that are traditional in appearance (smooth backs) are 8 3/4" rear ends. A 9" chuck goes right in there but when the olds/Poncho rear was the most popular the Ford was still an 8 3/4' rear. The olds was a stronger rear.

The olds/poncho rears weakspot was the axles. They would break in the splined area. real racers used aftermarket axles or had their axle splines hardened.

Here is a little known trick, that some of the chevy racers used in the early '60s. The Olds chuck was a bolt in for the early '60s Chevy rear. So if you had an early '60s coil sprung car with a drop out rear and wanted to beef the rear you could bolt the olds chuck in it with the heavier olds axles and you were golden.

The olds rear today is as scarce as hens teeth and the cost is right up there with unobtainium. If I could find the rear that I wanted, to go in my gas class stude for instance and money was not an option I would be after the olds. As it is I am probably going to have to use a smooth back housing that i have and stuff it wih a 9" chuck. but the olds is way more desirable for a performance oriented traditional car.

 

From what I've read in the past, P n B er' is usually right on. However, there is NO WAY an O/P, 57-64, 9.3" THIRD MEMBER, of any year, is going to bolt into the HOUSING of ANY YEAR Chevrolet HOUSING. 55-64 full size Chevrolet cars, 55-62 Vettes, and 62-63 Nova/Chevy II HOUSINGS all take the same THIRD MEMBER (However, the early Nova/Chevy II is a light weight third member as far as casting thickness, bearing sizes, axles, etc goes). IF it was possible to do an O/P THIRD MEMBER swap into the coil spring rear Chevrolet cars (58-64), everyone would be doing it. I don't even think an O/P coil spring HOUSING will even "bolt in" to those cars without modifying the brackets/spring pockets.
I finished assembly on my 57 Olds rear end this weekend by welding on the spring perch pads to go into my 56 Sedan Delivery. The stock Olds HOUSING has the pads further to the outside than a 57 Pontiac; 57 Pontiac are in the same location as tri-five Chevrolets, and is therefore, a direct bolt in.
The "old racers trick" is just not a true statement, so don't run out and buy a 57-64 O/P THIRD MEMBER to stick in your stock 62 409 Impala HOUSING, it just won't work. The 57-64 O/P THIRD MEMBER is "round", while the 55-64 Chevrolets, 55-62 Vettes, and 62-63 Nova/Chevy II's is somewhat "oval", and roughly, TWICE the size. Sorry P n B er', it's just NOT possible. Butch/56sedandelivery.

My 57 Olds HOUSING is loaded with a 63-64 Eaton Posi, 4.88:1 gears, and 31 Spline Strange axles. I wish I could post pics for comparison of the O/P-Chevrolet THIRD MEMBERS, the difference is HUGE.

 

I am pretty sure PnB was talking about the whole rear end swap. Third member, housing and all. The 57 Pont. is the same width as the early vettes and 55-57 chevys. The 57 Olds is an inch narrower. The O/P rears were much stronger than the Ford and Chevy rears at the time. Using all after market parts the 9" is the way to go.

I have been running the O/P rear in my 62 vette for 43 years. Once you get a stout engine and great traction, 31 spline after market axles start to shear, and Eaton posi's will destroy the spiders. Dana posi's, do not even bother to use, way to weak and they will crack the third member housing.

A 3 rib posi, 411 went recently on Ebay for about $950. The only thing I have found to survive is a 35 spline spool and axles. Yes, my car is a street car.

 

He's pretty specific about it being a "chunk"; chunk, third member, pig, and other names, used to describe the drop out center section. I know others have also made the same/similar claims. The brackets still won't cross directly over on the coil spring rear HOUSINGS. The 56 and older O/P rears do look more like the 55-64 Chevrolet, being somewhat oval, but even they won't fit. I think it's an old wives/racers tale being quoted. The ONLY way to beef up the Chevrolet unit is to use the MOPAR-Dana Posi/Sure Grip, with after market, MOPAR based axles, and use a 59-64 Chevrolet housing that the axles bearing ends have been enlarged/swapped over to fit the bigger bearing. The tri-five and 58 housings won't take the bearing (maybe if the ends were swapped?). See Aubrey Bruneau at BruneauPerformance.Ca, a Canadian Pontiac site PRIMARILY (Canadian Pontiacs having Chevrolet chassis and powertrains, and shortened Pontiac fenders/hoods). He campaigns a 62, 409, Super Stock car, and was running the stock, but highly modified, rear end. He sells the swap kits,and even a spool. P & B er' will have to clarify his statement for any of us to really know what he meant. Here's a TRUE oddity; for the 49-54 Chevrolet guys that want to convert to open driveline, they can KEEP the stock housing by using a 53-54 Vette third member, but the spring pivots have to be locked down. There's a 53-54 Vette, complete rear end on E-Bay right now, for THREE THOUSAND DOLLARS. Butch/56sedandelivery.

 

Glad to see this thread pick back up. What little I found out about using the Mopar 9.25 posi carrier in an O/P case suggests the ring gear bolt holes were elongated in the carrier to allow the use of the O/P gears. Maybe someone here has actually done it and could share some info. The off road crowd speaks well of the 9.25. Maybe it could be a cost effective swap. For the Chevy, I enjoyed the info on the Dana 44 side gears and spiders (came across that in the jr. stock thread). I would get new axles for either swap. Thanks, JohnnyD.