[wd45gto]

what would be all involved in putting a 9.3 out of a 61 Catalina in a 64 tempest.
i heard that back in the day they didn’t narrow them,so i am thinking of going that rout .

[Sirrotica]

If you can find one, a 58 only, Pontiac housing has the same lower control arm mounts as an A body, the upper control arms mounts will need fabricated. Since this was the year before Wide Track came about, the track width was close to the stock factory 8.2 width. It was a popular swap back in the 60s/70s to replace the rather weak 8.2 that the factory used with fairly minor fabrication.

[tom s]

I dont think it would be a wise move,limited gear selection,replacement parts are expensive.A ford 9in would be a better unit if you want a drop out 3rd member.Tom

[wd45gto]

A ford rear is out of the question.

[mgarblik]

If a 9.3" is what you are set on, and a 58 housing will install without major fabrication, that would be the way to go. The only other hurdle may be the cost. I recently rebuilt a 9.3 for my 62 Catalina. A new ring and pinion, all new bearings and seals and a fresh posi-unit, and I was very quickly in the $1300.00 range just for parts! A rather staggering figure and you will still have OE quality axle shafts. It's not an inexpensive venture.

[wd45gto]

I already have a 61 housing complete with a 3.42 posi. I also have 2 other housing of unknown years. One is just a case the other is in a 64 lemans convertible..building a gasser so lower control arms will be cut off for 60in ladder bars.just wondering about should I narrow the 61 or leave it alone...I read that they didnt narrow them back in the day.

[wd45gto]

Straight axle ,4 speed m22,bored and stroked 421 m/t intake and carter carbs.

[tom s]

I used a 58 in my 63 421 tempest,used Moser axles.As I said in post number 3,not a good choice IMO.Tom

[60man]

Spool it. Spiders won't last long with slicks and power.

[Sirrotica]

One other thing to keep in mind when looking for rear housings is that Olds also used the same rear axle setup as Pontiac, but I believe the track was narrower than Pontiac (no Wide Track). The 61 housing you have is going to require you cutting the rear quarters out for tire clearance, without narrowing it. Narrowing the 61 housing may save you a bunch of time looking for the correct width housing in junkyards and internet searches, as the supply of parts cars is by now fairly limited, even if you expand your search to include Olds parts cars.

My advice if you don't want to narrow the 61 housing would be to measure the 10 bolt width and try to find a big car axle housing about the same width or possibly a little narrower. The 58, from memory is quite close to if not the same width as the 10 bolt is. 55-57 are also narrow, but used leaf springs. Using the leaf spring housing would be fine if you intend to build your own rear suspension with ladder bars anyway.

No matter which way you go with a 9.3, you're using obsolete parts, as Tom mentioned, that are going to be very scarce and are not supported by many aftermarket vendors (more expensive than the FoMoCo alternative). Good luck and happy hunting no matter which avenue you choose....................

[jimmy daniel]

I’ve had a 9.3 under my 63 Tempest for years with no problems. I believe it is Fabtech that sell anything you could ever want.

[tom s]

Thanks to Brad at Fabcraft we have replacement parts,just VERY expensive compared to any other choice and limited gear selection.Richmond still makes some ratios and Brad has some made special for him.Tom

[Tom Vaught]

I was at Union Grove Race Track one night and saw Rick Johnson (62 Catalina) with a Spool, etc) break the nose off a 9.3" Pig that was in the car with his slicks as he left the line. We are not talking 14/32s here. NSS Car.

So to build a 64 Tempest with a 9.3" rear as an Altered Chassis vehicle would be cool and 'period correct' but that rear is not that strong with decent power.
Rick Johnson had his 62 Catalina on a diet so the Cat and the 64 Tempest might be similar in weight.

But it IS your car so do what you have to do.

Tom V.

[J.C.you]

here you go or someone else.....I am putting my 66 abody with 9.3 rear back to stock/ street and selling the frame and moly cage that will certify to 8.5.

The modified stock frame, complete narrowed 9.3, extra gears/third member, with complete ladder bar setup with coilovers, wheelie bars, wilwoods on 4 corners, manual rack and pinion and modified front crossmember for big pan. $4500

[jimmy daniel]

I’ve never had an issue with mine. I bought the billet caps, 4:88 gears and spool from Brad. I leave on a trans brake every pass. At one time I had a 1000 HP BBC in the car. It’s worked well for me plus was period correct. I’ve got the 463 Butler Motor in there now so it’s all Pontiac.

[Tom Vaught]

We are talking many years ago when this happened Jimmy. 1992 time frame.
I am sure that parts for the 9.3" rear are more plentiful with the NSS guys running their cars for many years now. Plus the caps did not fail, he broke "the nose" off the front of the case. Billet caps would not have helped that deal.

Tom V.

[tom s]

The race guys run spools,the street guys really cant.The weakest part of the 9.3 is the posi carrier it self.The bolts holding it together stretch and the side and spider gears loose their mesh and strip the teeth.Not sure about the 64 spicer carrier as it is one piece.All 57-63 9.3 posi carriers were the 2 pc design.When Tom diff was still in biz Tom drilled my case and put larger bolts and never had a issues with it after that.He said he would never do another as the material was just too hard to drill and tap.

[Doug]

The rear track width of both a 1963 Tempest and a 64 Tempest is 58”. The rear track width of a 1961 Pontiac rearend is 59.3”, a difference of 1.3”.

57 Pontiacs used leaf springs. 58 thru 64 Pontiacs used coil springs. I think Olds used leaf spring from 57 thru 60 and coils thereafter.

From Hollander listings, 57-58 Olds axles are 29 1/8” long and 57-58 Pontiac axles are 29 5/8” long, a difference of 1/2” in length. (Apparently however, the 1958 Olds with air suspension had 29 5/8” axles. I assume they used a “coil spring” 58 Pontiac rear end.). 57-58 Olds and Pontiac axles are 29 spline axles.

59-64 Olds axles are 30 1/2” long and 59-64 Pontiacs axles are 31 7/8” long, a difference of 1 3/8“ in length. 59-64 Olds and Pontiac axles are 31 spline axles.

The 57-58 Olds used 2” brakes, the 57-58 Pontiac used 1 3/4” brakes. Both Olds and Pontiacs used 2” brakes 59 thru 64.

The 31-spline 59-64 carriers will mount in 57-58 Pontiac and 57-58 Olds housings but the 57-58’s are 29-spline axles. It is my understanding that when installing a 61-64 Pontiac unit in a 57-58 (and maybe later?) Olds housing, a small amount of grinding of the housing may be required for clearance. I am not aware that any grinding is required when installing a 61-64 Pontiac unit in a 57-58 Pontiac housing.

It is my impression that, because of their design, for any year (57-64), none of the Pontiac (or Olds?) axles can have the splining extended back to full length when you shorten the axles. Shortened axles may not fully engage the side gears of the differential.

New aftermarket axles of proper splining and length may be needed when mixing and matching 1961-64 carriers with 1957-58 housings. For axle splines, the more splines, the “stronger” the axle. 29 spline is weaker than the 31 spline.

In the current aftermarket, axles and differential components of 40 splines are commonly available. Likewise, you can now get aftermarket 31 spline axles to fit 57-58 Olds and Pontiac housings with 59-64 differentials.

The 61 posi is not the stronger unit of the posi units used in 1959-64, the 64 unit being preferred. Since you are building a “gasser”, it is likely that you will not be using the 61 posi differential and 3.42 gears.

It appears the overall width of the housing is the main issue. There is a long history of using 57-58 Pontiac or Olds rearends for their strength in modified 63 Tempests which have the same 58” rear track width as the 64 Tempest. It seems logical to use an early Olds or Pontiac for a 64 “gasser”. They were widely used in gassers back in the day.

Leaf spring/trailing arm suspension bracketry is not an issue because the plan is for significant changes to be made.

A complete 3.42 geared 1961 posi rearend has a worth of many hundreds of dollars. It is likely that it could be sold for enough money to purchase a spool and aftermarket axles, as needed. Costs of certain items like gears, bearings, etc. would be the same whichever you use.