Can somebody explain differences in 10 bolt 8.5 posi with 342 gear to lets say a 12 bolt posi. My car is a 67 Camaro with a stock 10 bolt and everyone keeps mentioning needing a 12 bolt posi unit for durability and strength. Did first generation camaro's come out with 10 bolt 8.5 posi units. I really don't understand the options out there and would like someone to give me a run down on what best. Thanks

do a search on 10 bolt 8.5 and you will find lots of info. many believe it is (or can be built) as strong as a 12 bolt. either one can be a posi.

now if you have an 8.2 10 bolt, that is another story.

Mark, is there a way to tell difference between a 8.5 and 8.2 and did first gen. camaro's come out with 8.5. The reason for asking is to know if there are any problems with fitting to car without any cutting or anything like that.

See here for the differences:

http://www.novaresource.org/axle.htm

If it is an OE 10-bolt, it is an 8.2. Searching "8.5" and "8.2" here should get lots of info, as it discussed a lot.

Eric, thanks for info. A local person has a 10 bolt 8.5 for sale out that he has in a 68 camaro. Just wanted to be informed as possible before looking because I know absolutely nothing about rear ends. I am leaving in about 15 minutes to go and look at on lunch break and don't have much time to research like I usually do. The pics off novaresource.com helps a lot. Thanks again

10 bolt is just fine. Had a 10 bolt in my 69 with an auburn posi unit and 4:10's. Car saw the track on a regular basis with slicks and never had a problem. Ive snapped a few drive shafts ;) .., but never a problem with the rear..

Was that with the 8.2" 10 bolt? I had a 68 Camaro with a 700+ HP 540 in her and my 10 Bolt held up fine it that too. Granted now I did not run it at the drag strip with slicks on it but still with 700+ HP slapping it around on the street I was impressed with it's durability.

8.2" is working for me so far. :D
http://s10.photobucket.com/albums/a130/Dougs68Camaro/th_DSCF0005.jpg http://s10.photobucket.com/albums/a130/Dougs68Camaro/th_140016953-L-1.jpg

run your 10 bolt and when/if it blows up then hunt for a 12 bolt.. I bet that 10 bolt lasts a long time...