[APFU]

I've tried searching and haven't really found exactly what I'm looking for. I'm in the process of doing a "pro-touring" type of restoration on the car and am trying to get the brakes and such figured out so I can get this thing back on wheels and rolling around.

So first questions, What axle do I have in my car? I know it is not the original axle, I believe the original would have been a 12-bolt. I believe it is a Buick/Pontiac 10 bolt v. a chevy 10 bolt because of the scallops on the diff cover at 9 and 3 o'clock, is that correct?

It is a 10-bolt. It has a casting of 9793235 and a gear code of ZH. There is an "N" cast into the front of the carrier.Is there anything else you need to identify it? (I was thinking it is from a '68? with a posi? and 3.55 gears?)

I thought it was out of a 1970 GTO, but the more I look into it I'm not sure if that is correct. I also would like to know if it is a c-clip axle. From what I have read I believe it does not, but wanted to verify this without having to open the rear.

Second Question, does anyone know if there is a rear disc conversion kit for this axle. I've tried searching several vendors but the flange offset measurements they have listed don't seem to match the measurements I took from the car. I would prefer to put a Wilwood kit on the rear as to match the front but am open to other ideas. My rough measurements show the axle with a 2.5" axle-flange offset. The bolt pattern looks to be about ~3.08" across the top, about ~2.6" across the bottom with a vertical difference of ~2.45"

Thanks, your help is appreciated.

[GStage1]

You need to list your state in your header......are you Brandon FL?

Your car originally had/has an 8.2" rear. The rear driveshaft u-joint is held in place with 2 U-bolts.

I would strongly suggest you remove the rear and find a 71-2 Cutlass/Skylark corporate 8.5" rear which uses 4 bolts and 2 straps to hold the rear u-joint in place. You will need to shorten your driveshaft 1" for the 8.5" rear installation. See www.buickperformance.com and I have an article on there for a nice rear disc conversion. Do a cost comparison with Wildwood and see which is better for your set-up/intended use.

[APFU]

Thank you for the information George, I will definately keep it in mind. However, I would prefer not to have to find/refurbish/replace the rear and shorten the driveshaft that is currently in the car if I don't have to. At this point all I "need" to get this car back on wheels is a disc brake kit for the rear. If/when something in the rear brakes then I would definatley consider upgrading to a stronger unit with more aftermarket support.

['ol Pinion head]

'It is a 10-bolt. It has a casting of 9793235 and a gear code of ZH. There is an "N" cast into the front of the carrier.Is there anything else you need to identify it? (I was thinking it is from a '68? with a posi? and 3.55 gears?)"

Don't have my Nodular Pontiac casting number list handy, we're at a ball tournament this weekend. Is the N centered on the nose of the housing? The original '68 Pontiac Nodular A-body hsgs I built had the N cast slightly into the side of the nose of the hsg, while the '69 N casting & '70 N casting housings had the N centered on the nose of the housing. Each year is different 97xxxxx casting number for The N housings.


Recommendations... Going Protouring, either tuck away, or sell off the 3.55 HD Safe-T-Track to a hardcore restorer. A built up 8.5 A-body rear is the way to go in any good handling A-body, esp Protouring buildups. The 8.5 A-body axles's tapered axle bearings are best suited to side loading of wide tire & wheel combo's, & the 8.5 A-body can be built up to live under a GOB of torque for less $$$ than a same strength 12 bolt. How do I know this, been building 'em all for last 15 years.

Sealed (ball bearing) style axle bearings, like those used in all GM bolt-in axle applications up through '69 were not designed for wide tire & wheel combo's, but for the days of 7.75 x 14's on 5.5" wide wheels. Every year, I ship out a dozen or two good used sealed bearing axles to replace chewed up or broken A-body sealed bearing axles. Many times such sealed bearing axles have had an axle bearing seize, chew up the axle slightly, then pull through the bearing collar, resulting in axle coming out & damage to outer wheel house & 1/4 panel Even GM & Ford realized the limitations of sealed axle bearings & basically did away with them in bolt-in axle applications. Not by coincidence, the change to tapered bearing axle bearings came about as GM & Ford started installing the 1st 60 series rubber under American musclecars.