[Txbobcat]

Went to Missouri to see a friend who has a Pontiac junkyard. While I was there he mentioned he had a 323 posi rear end in a 65 catalina wagon that came with a 421 and air bags inside the coil springs. The price was real right and I had the cash so I took it home with me. I will be getting it installed probably next week in 65 cat convertible. This will be the third and final change as I went from a 241 non posi to a 259 to a 273 posi. I cant wait to take it for another drive.

[mgarblik]

I had a 3.42 limited slip in my 66 421 tri-power 9 passenger wagon. It ran 14.60 @98 MPH @ 5040 Lbs. You will love the change. Drove it at 60-65 MPH on long trips all the time pulling a 19ft.boat. The air bags in the rear springs, which I also used, worked great, especially with 6-8 people in it and the boat loaded with gear out back.

[OHCSprint67]

Hey Bob
I have a 3.08 posi in my 66 Catalina wagon, seems like a good compromise for the type of driving I will be doing with it when it's back on the road.
It should be fine with the 428

My 66 Bonneville convertible came standard with the 3.42 posi because of the 4 speed transmission.

Ron

[Txbobcat]

I wish that 421 had still been in the car. If so I would have carried it home as well. All the wagons I remember seeing had 389s. I never knew they had the air bag option either.

[Teej]

How was the rest of the wagon?

[AROWHED]

Nice score! The 65 posi case has a smaller diameter spider gear shaft (and consequently weaker spider gears) than I believe 1970 and up, but its not a real worry unless you got a lotta HP, slicks, and your right foot weighs 100 lbs.

[66bonne]

Nice score for a good gear.

Jim

[Txbobcat]

The rest of the ass end of the wagon looked pretty decent and the passenger side was good to. I never walked around the front.

[OHCSprint67]

Hey Bob
Is the stainless outside trim still there on the drivers side quarter window?
The drivers side quarter window moldings turned up missing when my wagon was delivered from Washington State to New Jersey.
Are there any stainless moldings still there around the door windows?
Mine was mostly a low optioned wagon, except for the 421 and the rally speedometer.
The stainless around the door windows dresses the wagon up a lot
Thanks, Ron

[Txbobcat]

OHC pm sent

[Ragtop Man]

One more time, because I'm tapering my meds (well, some of them) Have the Wallace Racing chart, and the GM axle chart but it doesn't tell me

Which posi units for '65-up diffs will fit an open 3.23 from a '66 2+2?

Of course, a 3.23 posi is a drop swap.

But what is necessary for the rest? I'm writing off any 342-355-373s because those are unobtanium these days.

Our local CL has 2.93 range posi from time to time... but do not want any more greasy giant hunks of iron in the garage than necessary.

Likewise, how different is the posi from the '71-6 big car rear axle?

Thanks, and this time I will print it out and write it down!

[AROWHED]

http://www.teufert.net/fullsize/rearends.htm

You can use the 2.73 - 3.08 (mid-series) differential case with a 3.23 gear, if you get a ring gear spacer.
Likewise, I have a 1972 mid-series posi differential (originally held 3.08s) in my 1965 rear axle housing, but it has the recently introduced 3.55 gear that Fabcraft was offering, and that 3.55 ring gear is thicker so as to allow use on easier to find mid-series cases without the need for a ring gear spacer.
The 70s differentials use C-clips to retain the axle shafts...that is the main difference. These diffs will slide right into a 65-70 housing and work just fine with the 60's bearing retainer style axle shafts. Same spline count, 31 if I recall.

[Ragtop Man]

What if I have the 3.23 rear original to car and just want to add the posi? Still add the spacer?

[63gpman]

Correct the 2.93 gear housing is a 2 series carrier and the 3.23 is a 3 series carrier. You can use a ring spacer to make the 3 series gears work with the 2 series carrier. I have a couple of used series 2 units along with the spacer and correct length bolts needed that I would sell for $250 + shipping if interested.

[Ragtop Man]

Thanks 63 GP man for the help - much appreciated.

Sounds like I need to bite the bullet and track down a proper 3-series posi unit for my car - it's stone stock (well, now) and after all the footwork of spacers and other units, it would probably be better to look for the 323-up.

Many thanks for the tech assist!