[v8liveson]

I have an original GM posi carrier out of a 68 Firebird for sale. I bought it from a friend who removed it several years ago to install some open highway gears for cruising. It worked good. I'm 80% sure it is for 2.94 to 3.23:1 gear ratios. I could not find any useful casting numbers to help me identify the ratios. (The other 20% possibility would be for 3.31:1 and higher ratios.) Feel free to chime in if you can tell the difference from my pictures. Also includes a set of ring gear bolts.

Price is $300 plus shipping. Located in the Minneapolis, MN area. Call Matt at 715-410-465six if interested. Thanks

[v8liveson]

Still available. If any of the experts out there can confirm the series of the carrier, it would be much appreciated. Thanks

[patox]

Dont you happen to have some highway gears too?

[v8liveson]

No, I don't have any gears.

[68 Firebird Brian]

Originally Posted by v8liveson

Still available. If any of the experts out there can confirm the series of the carrier, it would be much appreciated. Thanks

Do you see any part nos on it?

[v8liveson]

Just a patent number, and a random '101' number. I tried searching those numbers but did not find much. Maybe the '101' means something?

[68 Firebird Brian]

try this...https://firstgenfirebird.org/forums/...01&type=thread

['ol Pinion head]

Set the carrier on the drivers side carrier bearing, measure up from workbench surface to the machined ring gear mating surface, then do an advanced Search for Pontiac 8 2 carrier, am sure I've answered this half a dozen times. If cant find answer, can go out in shop & find a low ratio Pontiac 8.2 STT carrier & measure.

[v8liveson]

Pinion head- the measurement is 1 13/16". I attached a picture just to make sure I'm measuring correctly.

[v8liveson]

Brian- thanks for the link. I think it helped verify the carrier I have is the mid ratio (2.93-3.23) one. The carrier in the link had a 3.90 gear on it, so it's for the 3.36 and up series. I studied the pictures and compared to mine, and I noticed one key difference. See attached pictures- the measurement between the red lines is what is different. This is what tells me that mine is NOT for the 3.36 and up series. Therefore, mine has to be for the 2.93 to 3.23 series.

The first pic is from the link above (the 3.90 carrier). The second pic is from mine. Am I on the right train of thought here?

[AG]

The distance you need to measure is from the surface the carrier sits on to the ring gear mounting flange vertically, not the ones indicated in red. Put a straight edge on the mounting flange and measure up to it.

[v8liveson]

AG- right, that's what I measured in post #9 (my reply to pinion head). In post #10, I pointed out the different distance I noticed between the red lines, which perhaps is a reflection of the different distances I measured for post #9? If the pinion gear mounting surface height is variable between the different carriers, then wouldn't the distance between the red lines change also? I'm making some assumptions here, but perhaps it is helpful in narrowing down the correct carrier?

Thanks all for your continued help, I appreciate it.

[68 Firebird Brian]

Originally Posted by v8liveson

Brian- thanks for the link. I think it helped verify the carrier I have is the mid ratio (2.93-3.23) one. The carrier in the link had a 3.90 gear on it, so it's for the 3.36 and up series. I studied the pictures and compared to mine, and I noticed one key difference. See attached pictures- the measurement between the red lines is what is different. This is what tells me that mine is NOT for the 3.36 and up series. Therefore, mine has to be for the 2.93 to 3.23 series.

The first pic is from the link above (the 3.90 carrier). The second pic is from mine. Am I on the right train of thought here?

Contact Jim (see attached), he will know exactly what it is. I got all my parts needed to rebuild 2 rear ends from Jim. Everything was stock and it fit!

[monzaz]

that is a 2.93, 3.08 and 3.23 carrier the mid 3 series carrier
The steep 4 series carrier 3.36 - 4.33 and beyond is 1 15/16" to 2" height the way you are measuring.
The lower freeway 2 series is 1 1/2" to 1 5/8" (ratios are 2.56 and 2.78 )


Merry Christmas !Hope this helps you out.

Jim Mitschke
JD Race

[monzaz]

This is the same for Posi or Non Posi carriers


just to be clear
NOW watch out as BUICK in 1968 -1970 has its own carrier you will run into at swap meets - their measurements are slightly different than the Pontiac and early BOP 67 and older PLUS the fact that the Buick carriers have larger driver side carrier hub and bearing.

They have 4 carrier breaks where pontiac has 3 carrier breaks.

The unit you have pictured is a early 64, 65, 66, 67 lower horse power posi unit
only 6 bolts that hold it together and you can see into the cone cavity and see the casting that holds the bearing on has BIG windows...THIS weakens the casting
Super duty and later posi unit do not have this which they thought was a good way to get fluid to flow through the unit etc.

The ring gear bolt holes should be for 3/8" right hand thread bolts
LAter in 1970 -1972 and maybe even late 69 the Bolt holes were drilled larger to handle the 7/16" left hand thread bolts they still use to this day in the 8.5 and 7.5 rears.

Aftermarket posi units will need to be drilled to make the 7/16" bolt fit through the case and into the 1970 -1972 ring gear 8.2

Hope all this info helps. Jim

JD Race

[v8liveson]

Thank you Jim- much appreciated. This is why I love the Pontiac community- people are always willing to help. The ring gear bolt holes are indeed 3/8" right hand thread.

And it is still for sale, if anyone is interested in 2.93, 3.08, or 3.23 posi.

[v8liveson]

Sold- thanks PY