do these look good? I'm just trying to figure out the cheapest way to get my rear end done. I've got $200 and luckily my axles and bearings look good according to the guy that is helping me set up the new gears when I get them in. questions, comments, and suggestions are welcome. Thanks
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&cahttp://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33731&item=7945491023&rd=1 tegory=33731&item=7946254146&rd=1

what gear ratio are you looking for? summit has some richmond 4.10 gears for 165 bucks plus there 8.95 shipping.......the cheap route would be to find a good used set and install......thats what i do look for used gears to put in.....

I've been recommended to use 3.73s so I won't run out of rpm on the highway. right now I have 29" tires on the back and my 2.73s disagree with each other real bad. will I need a new crush sleeve and stuff or can I just replace the ring and pinion? most of the gears I think I've found were from friends but instead of being for 8.5" 10 bolts they have been everything else like 7.5" camaro rears, 1 ton truck rears......
I just want a gear that I can have fun at the dragstrip but not run out of gas on the way there. my combination is below if anyone has an opinion. I want to get this done before the end of this month since I've been putting it off so long.

Zac

are you absolutely positive you have a 8.5 10 bolt? your car SHOULD have an 8.2.

The guy on ebay has excellent feedback. Looks like he sells gear sets.

need to find out for sure what rear end you have and yes a new crush sleeve should be put in....i think the last one i got from the dealership was like 8 bucks or something fairly cheap.....good idea to grab a new nut too for the pinion....i have reused everything before and not replaced nothing but it was just for a short lived set up...there was no plans for a lot of street driving......kinda a temp. set up that involved no money......it doesnt bother me to run used gears ..infact i have bought more used then new and have really good luck with them in the set ups....anyway...a set of 3.42 would come by real cheap like on ebay or some other place i can usaully get these for about 30 bucks since they are just stock gears....of course there are many ratio's avaliable just giving you an idea.

Originally posted by RatONaStick:
Zac

are you absolutely positive you have a 8.5 10 bolt? your car SHOULD have an 8.2. I thought only '64-'70 chevelles had the 8.2 and the '71 '72 chevelles had 8.5s exept SS. according to my 1971 chassis service manual there are codes on the "right axle tube 3" out board of the differential cover being a B-buick, O-oldsmobile, G-chevrolet gear and axle, K-gm of canada, M-gm of canada, or P-pontiac..." "...All Cevrolets exept P and M type axles have 8-1/2" ring gear diameters. P and M type axles have 8-7/8" ring gear diameter. I don't recall my axle code so I'll have to look in the daylight but according to the chassis manual the only rear ends you could get in 1971 is either a 8.5" 10 bolt or a 8-7/8" which is a 12 bolt. My build sheet specifies the gears to be 2.73 and non posi.

from past posts here i was under the impression that the 8.5 10 bolt was first used in late 72, and finding one in a 72 chevelle is rare.

an easy way to tell is to look at the diff cover.

the 8.2 has a raised ridge across the cover that runs from axle tube to axle tube, much like the 12 bolt.

the 8.5 cover is completely smooth/round.

Originally posted by RatONaStick:
the 8.2 has a raised ridge across the cover that runs from axle tube to axle tube, much like the 12 bolt.

the 8.5 cover is completely smooth/round. mine definatly doesn't have a ridge. unless you are talking about the ring gear bump that is vertical?
'71 must have been a "conversion" year from the 8.2 to the 8.5 because looking at the winter summit catalog the ratech installation kit labels the 8.2 from '64-'71 on page195, but on page198 the Eaton posi ad says 8.5 goes from '71-'88 and just below that it says '64-'72 chevy car?????? also on page195 the summit overhaul kit says '71 and up. now I'm confused :confused:
do these rear ends require whale oil? I heard from an old guy that IF it needs whale and I don't use it the seals won't seal

dbl

Get under your car and look at the rear. The 8.5 has two distinctive corners/bumps sticking out from the bottom of the center section.

Here's a drawing of one:

http://www.4wheelnoffroad.com/diff/gm1085.jpg

That's a sure-shot way of telling an 8.2 from an 8.5

that's what mine looks like. I looked on www.chevellestuff.com, (http://www.chevellestuff.com,) I think it's pat kelly's site maybe (I apologise if its not), and it says that only some late '72s had 8.5s which backs up ratonastick. maybe it's not the original rear after all? it came from arlington if that means anything.

Zac

good deal, the 8.5 is pretty stout for a 10 bolt. just trying to look out for you, id hate to see you spend a bunch of money to find out you had a different rear end than you thought.

I replaced the rear end in my 70 that was original (I'm second owner), and it was a 8.2 10 bolt but it also has a smooth cover, not the inverted V that was suppose to be there. It doesn't have the two casting bumps on the lower side of the housing. Don't pay to much attention to the cover, the housing is the key.

you make a good point, im only thinking of the chevy rear ends.

the early BOP (buick olds pontiac) 10 bolts had a smooth cover, they also have bolt in axles(no c-clips).

Just to add to the confusion, my 70 came stock with the inverted-V cover. I took a smooth cover from a 71 wagon, had the smooth cover and was an 8.2

I think at some point both types of covers were available and both were used as needed.

I tore that rear end up today looking for the serial # with no luck, I went up and down the tubes with a wire brush. it does have 2 little triangle things on the bottom though. I think I'll just yank it out on sunday then ID it instead of ordering parts first.

I looked all over the place on mine for the ID, nothing there??

Looked on the 71 rear I had, not more than five minutes of searching and I found it.

If you are interested , I have some super clean used 3.73's for a 8.5" 10 bolt. I would like to get $75 bucks for them. I can send you picks of them if you like. Let me know via e mail. Thanks Ron

you have mail
about the #s maybe I'm blind

Pics sent..... graemlins/beers.gif