Who has different year, make, model rear installed into their X frame?

[Tom Miller]

I picked up an 8.5 3.73 posi rear from a 1986 442.
The G body rear is almost the same width as the stock 63 rear.
Going to do my best to build upper control arm mounts to triangulate the suspension and get rid if the damn panhard bar.
Pretty sure I can make it work.

 

[Tom Miller]

Here it is. Didn't load the first time.

 

[Don Jacks]

Just don't throw too much power at that 8.5 if it has the "corporate" posi unit,the carrier will break taking the ring and pinion with it.Usually about 400-430 is enough to result in failure.

 

[benchseat4speed]

I’ve seen those 8.5’s under some pretty quick vehicles, but always in a light car like a Nova or an S10 or something, and always with an automatic. Never seen one in a big car with a stick. I’m not real hip to the whole C-clip thing, and it really is nice when something breaks in the center to pull a 3rd member and leave the housing in the car. My vote is 9” or 57-64 Olds/Pontiac (with a 59-64 three rib case) Just my .02 tho.

Plus, those G-body 8.5’s are pretty darn rare aren’t they?? Maybe hock it to some grand national or monte carlo guy and make a few bucks

 

[Tom Miller]

This is the rear I'm going to use. Every bit as strong or stronger than a 12 bolt, won't spit the pinion out the bottom like a Ferd 9 inch, and parts are easy to come by.
Going to buy the lower mounts, and I'm going to fabricate upper arms and mounts to get rid of the stupid panhard bar.
I've got a good friend that BEATS on an 80 Impala with a 427SBC with an 8.5 every week to the tune of 10.70's-10.80's. Drives it to the track, usually wins or runners up, drives it home 45 minute trip each way.
His sons car has same rear, different car, 10.50's and 60's. Drives to and from the track.
You can break ANY rear under the wrong conditions, and you can make a weak rear live under the right conditions.
The 8.5 is NOT a weak rear.
Wanna break a rear?? Run those stupid drag radials on a crappy track. Once those radials start spinning and trying to grab/tire shake, you will bust some stuff up.
Radials might be worth a tenth over bias slicks in a perfect world on a perfect prepped track, but most tracks DON'T have perfect prep.
I wasn't going for a debate here, and I appreciate the input, I was simply telling what my plan is, and what rear I'm going to use to do it. This car is auto trans car.
I chose a rear that is strong, parts are common and plentiful, and not having the expense of narrowing or buying an expensive aftermarket housing.
This is a complete rear drum to drum 3.73 posi for $800.

 

[La Hot Rods]

Being it's out of an Olds, does this have C clips to hold the axles or are they bolt in?

 

[Tom Miller]

Being it's out of an Olds, does this have C clips to hold the axles or are they bolt in?

C Clip, so I'll install a c clip eliminator kit.

 

[La Hot Rods]

I have never ran any of the C clip eliminator, but have installed several.
I am not sure how well they would hold up for a lot of street driving. The bearings are not very big and look light duty to me.

 

[Don Jacks]

I haven't noticed lately,but a few years ago,some of them had problems with leaking gear oil.I have run 7.30's at 91 for years with no more than a mini-spool[track only duty] and stock axles in an 8.5.The weaker corporate posi unit broke once we got into the 750-7.60 range on a 3200 lb car with slicks.I've seen several in heaver cars that broke sooner.The corporate unit is the one with the "S" shaped spring for the posi clutches.They did make some with the Eaton unit [4 springs]that was bullet proof.T he problem area is where they machined the area for the clutches,leaving the case thin and that's where they break.The Ford Traction-Locks in the 9in.suffered much the same fate.I'm not trying to change your choice in rears,as imo,it's a good one,just trying to point out areas that you'll need to address.I spent over a quarter of a century bracket racing during my lifetime,and know of what I speak.You are free,and encouraged to do with your car as you wish.Good luck,just don't say you weren't warned.

 

[Skip FIx]

My 78 TA has an 8.5 with an Eaton posi and stock 28 spline axles and a lot of high 10 secopnd passes weighing 3750lbs and 1.5 60 fts. Before that a lot of low 12s @ 111 weighing 3900+ with a RAIV 400ci motor. All factory posis had the S spring and according to Tom at Tom's Differentials (RIP) they would break before the axles would. You can get a 30 spline posi and set of axles and get even a little more strength in them. They use the same bearings and pinion diameter as 12 bolts.
Some G bodies got the 8.5 many got the POS 7.5. There were some 71-72 Olds/Buick A bodies that used the 8.5 and had bolt in axles no C clips.

 

[Tom Miller]

Got the rear frame section sitting level on stands, and I used some threaded rod & 3" exhaust clamps to set ride height.
I measured ride height of my 409 BelAir, and matched it.
From here once I get the other rear in using the lower mounts, I can set the pinion angle and start figuring out the mounting brackets for the upper control arms.

 

[Tom Miller]

Boy, I thought most of my engineering was going to be figuring out how to make upper frame mounts and custom upper arms.
I haven't got past the lower control arm mounts......
The original 63 lower mounts are positioned quite a ways behind the center line of the axle tube, whereas the G body lower control arm bolt hole is about centered under the axle tube.
That and it looks like the 63 arms and mounts come to the frame at about 20 degrees, and the G body mounts and arms are at about 15 degrees.
Not giving up, taking this as a challenge now, GAME ON!

 

[tripower]

I have a hankorin for the Olds Pontiac 9.3. This is the 62 Olds 9.3 in my 61 Bel-Air. Doing the same in my 60 Bel-Air.

 

[blkss64]

Hey tri-power, good to see you back on the forum. You still down on the coast? I am still here in Seattle. Looking forward to seeing that Buick again. Have you any thoughts on the drivetrain on the new 62 project ?

 

[Iowa 409 Guy]

There's the beef.

 

[heddrik]

Nice set up! Are there many modifications to do this swap? Finding a posi rear off a BOP may be the toughest part, they've all been crushed. I have to admit I'm ignorant of differentials. Thank you.

 

[tripower]

Nice set up! Are there many modifications to do this swap? Finding a posi rear off a BOP may be the toughest part, they've all been crushed. I have to admit I'm ignorant of differentials. Thank you.

Its not a BOP. Its a 57-64 Olds Pontiac 9.3 and posi is easy to find original or Fabcraft https://fabcraftmetalworks.com/prod...I--1957---1964-OldsPontiac-93quot--Rear-Ends/ 58-64 Chev housing is 60" overall. The the 61-62 Olds housing is 61" so there are a couple differt ways you can do this, either with wheel backset. When welding the brackets on the housing the axle tubes will warp so in order to fix this the bearing cups are cut off and then aliened and welded back on. prior the welding the bearing cups back on we cut 1/2" off the end of each axle tube so when it went back together the Olds housing now measures 60" overall. Now you ask what about the axles? Looking a t the axles you can see a witness mark on the axle spline where the go all the way through the side gears and stick out the other side about a 1/4" I just cut the axle off at the witness mark and put it together. I did this on the rears in both my 61 Bel-Air and my 57 Buick and been burnen rubber ever since.

 

[409newby]

Hey Dan is that your old Yamaha G 2 in the first pic?

 

[tripower]

Hey Dan is that your old Yamaha G 2 in the first pic?

Hey Pat,
Yes that is my old Yamaha G2, sold it and bought the G22 I had at Great Bend.

 

[oldskydog]

Got a Yamaha G-5A for sale if anybody interested. In Az.