Will the gears from a 86 Monte Carlo fit into my 66 Suburban 12 bolt rear? If so, isn't it a matter of releasing the axle c-clips, sliding the axles out, unbolting the 3rd member, then reversing the process to reinstall? Or is this swap better left to someone set up to do pinion to ring lashing  etc.? I would like to find some better highway manners. It's gonna grenade my motor if I am to keep up with CA freeway speeds and not get run over with the current gears installed Thanks- Stan.  

No, the only thing common between the passenger 12 bolt and the truck 12 bolt is 12 bolts. And a 86 Monte isn't even a 12 bolt.

There are aftermarket gears available from local truck shops and the hot rod catalogs such as Summit. If this is a 4x4, the ratio at both ends has to be the same, that means 2 sets of gears have to be purchased.

Setting ring and pinion lash is very exacting, if your a good amature machanic you can do, if not if's a lot less expensive in the long run to have a pro set it up.

Bogie

Thanks Bogie, helpful as always. It's a 2wd, I am pretty mechanically inclined, but this is a grey area to me and could have disastrous results if not done correctly.

I guess I'll have to see if I can find a pro who'd be patient enough to allow me to look over a shoulder and give me the play by play. With this being said. What would be a good ratio to put behind my planned LS1/4L60e? The Sub is wearing 26 1/2" tall tires (not sure what that runs out to), and is planned to be dropped over the 86 Monte chassis. It will see cruise nights and would like it to be considered "hot street". Will the Monte rear be a good selection, versus the Sub rear? I'm leaning to the Monte because of it already being triangulated four link, and have a ride-pro air system planned to be installed. Other than the wheelbase having to be stretched, it was also a plus because of it being equipped with front discs. An entire plumbed and updated chassis seems really appealing. Would you advise for or against this planned chassis swap? Thanks once again for all of your wisdom.

hi great to hear of your project and how it is coming along. i know a trick that may put you ahead some... buick gn rear is a direct bolt in and uses a 8.5 inch carrier. this rear is really quite stout and shouldn't give you any problems no matter how hard you beat on it. my friend proformed some mods to this type of rear (mounting tabs...) alum jack shaft cover , good axles.... and put it under 531 inch big block astro van the thing is completely set up for race,turns 10.50's on 28x9's and hasn' quit yet after 3 seasons. good luck!

Thanks for the input, Bottle. I know my project isn't the most "usual". I'm trying to stay with the curve of "more widow" cruisers, that is all the rage right now. Because of having a family and wanting to keep it real for all, not the trend. I had originally started, but abandoned, installing an 8.1 litre/ Allison 6spd AOD into the Burb. It was fitting fine, but the milage/versus cool factor wasn't weighing near equal. This is a Hot Rod sport, not practicality, PTA meeting. Why not have a SUV that can lay the smack down on a ricer if the need shall arise? Besides, can you imagine the conversation after a family of four waves bye to an import light to light, then drops the bags after pulling into a cruise night? I think it'll be fun.

Is it possible to post pics of progress on this site?

I have a Z28 2002 camaro and rebuilding the rearend now on my own and help from alot of friends.Chevy hiperformence Mag has an artical in november 2003 ishue about how to rebuild a 12 bolt chevy rearend.Thats what I am using to do mine.Plus I have the dealer manual but thanks to that I broke my antilock brake sensor oh well another $130.00 

Is my 10 bolt Monte similar enough to your 02 Camaro to benefit from this tech article?  

Ya, I talked to alot of people on the phone in the last two weeks with this project  summit,nationaldrivetrain ,lavines machineshop danbury,The 10 bolt GM 7.5 from 93 to present and now 7.65 like mine are the same bearing rebuild kit part # and the gearsets are supposed to be the same You can call NationalDrivetrain to make shure and there prices are the best I found. I plan on changing my carier and axils as soon as I get the $$$ and thats where I'm going.Ya Nov 2003 12 bolt rear rebuld chevyhiperformance.

Oh ya you didn't say what year????  

My Suburban is a 66 and the Monte is a 86. Both are 10 bolts, but since posting this thread have learned that they are completely different, besides having 10 bolts. Which of these particular 10 bolts would be recommended to put behind my LS1/4L60E?  

    I was reading my camaro upgrade performance book for my older 1988. They claim rebuilding the 12 bolt with aftermarket parts or a ford 9" convertion for drags or racing. But on the street the 10 bolt 7.65 is the newer vertion of the 10 bolt. I'm not shure what year the 7.65 replaced the 7.5 but it is supposed to be a stonger rearend and with aftermarket bearings and axils and auburn or eaton carrier good for street racing of cource this book was writen by GM performance div.