[pggto]

I have a 72 Lemans with a 10 bolt 2:73 posi rearend in it, what gears will that unit accept? Thanks

[Txbobcat]

If you were going to change out that 273 i might be interested in it. [email protected]

['ol Pinion head]

2.73 is a Chevy 8.2 c-clip 10 bolt application (ala 10 bolt Chevelle through '72). Your 8.2 rearend should be a Pontiac 8.2 10 bolt if it is original to your LeMans & as such may be a 2.78. IF it is a 2.78, the 2.78 is a high ratio gear & fits the high ratio carrier, along with the 2.56.

The mid ratio carrier was used with 2.93-3.08-3.23 gears, & any of these gears will have to be sourced used.

To build the 8.2 Pontiac with new or very nice used gears, new Auburn or rebuilt 8.2 4 pinon carrier... talking some bucks...better off spent on a stronger 8.5 A-body rear, IMO.

['ol Pinion head]

pggto,
Hello. There were 3 different ratio 8.2 Pontiac 10bolt carriers for both single track & Safe-T-Track usage. I try & stock mid ratio & low ratio 8.2 Pontiac carriers, as occasionally use one in a build, the rest I sell off.

ID wise, below are the gear splits for the Pontiac 8.2's...

High ratio = 2.56-2.78
Mid ratio = 2.93-3.08-3.23
Low ratio = 3.36-3.55-3.90-4.11-4.33-4.56-4.88-5.something. For ID'ng singletrack carriers by any markings, I'd need a few good digital pics.

On the 12 bolt Chevy car rear, the mid ratio carrier was used with factory 3.08-3.31-3.55-3.73 gears. 3.42's are avail for these from US Gear-Strange, decent alternative, if can't find some nice 3.31's used. Usually have a set or two of 3.08's for these, seem to use up any nice 3.31's quite quickly.

[Randy Frazier]

First make sure that the rear end in your car has not been changed. It should have an 8.2 size ring gear and should have bolt in type axles with a 10 bolt cover. The stock ratios for a '72 A body were 2.56, 2.78, 3.08, 3.23, and 3.55. All of these ratios should fit the stock carrier except for the 3.55 which fit the h.d. 4 pinion type carrier that was used in earlier years through '72, and would also accept 3.36, 3.90, and 4.33 ratios even though these last ratios were not available in '72. One other word of caution is that in late '69 the ring gear bolts on some of these 8.2 rears were changed to 7/16 - 20 left hand thread bolts. This is more info than you asked for but in short, the 3.23 and higher ratios should fit your carrier if it is what you think it is.

[pggto]

OPH, If I understand this correctly this carrier will not accept 3:23 or 3:55 gears? How do you identify the different carriers? Would I need to find a different carrier to get the gear ratio I want? How many different size carriers are there? My 70 GTO has a 69 12 bolt 3:55, what gears will this one accept? Sorry for all the questions, but I don't know squat about rearends.
Thanks


Txbocat, If I figure what to do to change gears, I wouldn't need the 2:73's or 2:78's. I'll let you know what I decide.

[pggto]

I have a 72 Lemans with a 10 bolt 2:73 posi rearend in it, what gears will that unit accept? Thanks

[69GTODUDE3E]

Bob, I believe that's what's in my 72. I know they are highway gears...I really want some 3.55's

http://www.cardomain.com/member_page...=358363&page=1

[pugslyx234]

If i have a 336 open can i put a 256 posi unit in my housing its a 68 gto ?

[428GTO70]

Was it only the Skylarks and Cutlass's that went to the corporate 8.5 rear end in 71? If you do indeed have 2.73 gears and if that was NOT an 8.2 ratio, someone may have swapped an 8.5 rear in there. If thats the case you have the desireable 3 series carrier and can install your desired gears into it. Not to mention it is a good strong rear with plenty of parts to choose from as it was used from like 71 up till now I think. Another good thing about the A body 8.5 rears is they had bolt in axles unlike the newer ones that used c clips.

Holy crap I didnt realize this post was 2 years old, never mind pggto, im sure you have it worked out by now. Thats some big time grave digging woody. As long as you are swapping the whole insides of the rear i think you should be fine, I dont think they made different axle housings for the different series carriers. You will need to use the same ring diameter carrier and gears though, you cant put a posi and gears from an 8.5 rear into an 8.2 rear end.

[pugslyx234]

Thanks i,m sticking with 8.2 just changing carriers. I sometimes dig to dee,Also is there 28 and 27 splines ?

[mskrom]

Hey everyone-
Sorry about this, but I need to resurrect this thread. I have a couple of questions about changing out rear ends and gears. First of all, my 66 has 3.08 gears in the open axle. What I would like to do is to move to a safe-t-track rear end- possibly 3.55 gears. From reading through the earlier posts in this thread, do I understand correctly that I will a) need a new rear end, housing and all, and b) need to be able to determine what series of safe-t-track axle it is before I know what gears I can put in it?

Also, what is the difference if gears are left hand thread or right hand thread? Is one better than another?

Finally, my understanding is that rear ends from 65 and 66 cars will be interchangeable, same dimentions etc. Is that correct?

Thanks for the help!