I am completely rebuilding a 12 bolt rear end for my 72 chevelle, it needs to handle approx. 475hp - 475tq for now, maybe putting a big block in later or rebuilding a 400sb to pushing as much hp - tq as my money can get me.

Currently 12 bolt non-posi 2:73(I believe)

Want 12 bolt posi 4:10

Building this rear end is not going to cheap so I am hoping to get some input on the compatibility and quality of the components I have selected, they are as follows:

Axles - Bearing - Seals
Superior Axles, Evolution Series 30 Spline Rear Axle Kit
Summit part number SAG-EV12-1
or
Moser Engineering Replacement 30 Spline C-Clip Axles
Summit part number MSR-A123003


Gear Ring and Pinion Sets
Richmond Gear Series 4 4:10 Ring and Pinion Set
Summit part number RMG-6900311


Posi Unit
Eaton Posi Clutch-style limited slip Series 4
Summit part number ETN-19555-010


Install Kit
Richmond Gear Installation Kit
Summit part number RMG-8310191

I would need to get wheel bearings and seals if I go with Moser axles instead of the Superior Axles kit.


Any help is greatly appreciated.

406chevelle

the only link that worked was for me was the Eaton posi. I just re built my 12 bolt truck with one, I used a Richmond gears 3.73 set and a raytec install kit, so far no problems and will hold up fine, I used superior brand axles and had to machine 1/32" off the very end of both for the spider gear pin to slide in. If your looking to put some power to it get Moser axles, they are guaranteed against flex and they warranty them, and defiantly get a girdle rear end cover helps keep flexing down. Iv seen built 350's in G bodies break gears like crazy, then put a girdle cover on and never have a problem.

http://store.summitracing.com/partd...15&autoview=sku

71 c-10,

I appreciate the quick reply and letting me know the links did not work.

I was considering the Moser axles but went with the Superior Axles based on the wheel bearings and seals included for the same price, if the Mosers are a better more reliable product I will need to do more research and possibly reconsider them. I also like the fact that the studs are screw in on the Superior Axles, not sure of the benefit there.

The girdle looks to be a good idea also, I looked at them earlier but the price pushed me away, the money to build this rear is already a big bite in the rear, but I guess it would be cheap insurance on all the money spent.

406chevelle

I used the Ratech deluxe install kit, it came with every bearing race seal bolts shims and gasket to do every thing. I know it ain't cheap but it's what puts that power to the ground. I would think, unless your running slicks, press in studs would be ok, thats what i used, new studs and nuts were 20 bux. And i think the 30 dollar price diff would be to go with the ratech kit with everything, although, i believe the ring gear bolts i got with mine were like 5 threads to long and bottomed out, i re used the old ones with out a problem. What you have picked out will be a stout rear end combo and if you do a lil looking at this and that you may be able to save a few bucks, not sure tho. With the axles it's probably a toss up what ever works for you, I have the Superior axles in my c-10 and my blazer and they seem great and a good quality, granted I have the "stock" type replacements so im sure the EVO sets are even stronger. You may want to consider looking at I think jegs and on ebay for auburn units, I know a lot of ebay stores have brand new auburn posi and Richmond gear sets for 12 bolt car. Auburn posi use cones instead of springs and clutches that can wear out, there supposed to be a lot stronger i think but can not be sure, worth a shot to do some research into. glad i could help keep us posted on what you do!

I am building a GM 10 bolt 8.2 in my 66 chevelle. I bought moser axles but they told me no warrenty. superior has a 10 year warrenty so they were a close second. i bought US GEAR (strange) gears 3:73 and a yukon complete rebuilt kit. i bought a summit girtle cover expensive but good insurance for my 8.2 (weak) rear end!! i also bought a eaton posi, suppose to be better then Alburn!! I bought everything off a guy on ebay saved about $90.00 but some parts were old and some not boxed very well!!

Doug 66 Chevelle 406 SBC

9 inch, all the way. My dad's 70 would spit out muncies and 12 bolts every time he dropped the clutch (when you're young, you're stupid, right) so when he got his GN the first "big" mod was a 9". he hadn't even went into the engine yet.

12 bolts are a great rear end. I have one in my 3700lb Chevelle that pulls 1.4 second 60' times.

Go with the Eaton differential. With the 4-sereies, the highest gear ratio you can have is a 3.73. If you use a 3-series, you can use 3.08-3.90 and then 4.10 and up with a spacer.

Welding the axle tubes to the center section is a good idea. You can do this with a wire feed welder.

An alternative to the girdle is installing a steel cap on the left side carrier bearing. This does require some time to fit it, and a tap for the larger bolts.

I agree with galaxe go ford as you can buy the complete housing axles and center section for about 1500.00. If i was going to put down the horsepower i would do it in a heartbeat. You are going to wind up spending about 800.00 or more on the chevelle so go with the 9" ford and also you can have several gear changes at hand and switch in an hour and go

Sounds like you already bought the Superior axles. Good choice. IMO they are better then Moser. IIRC Moser (and Currie, and Dutchman) uses Superior blanks (they may have multiple blank vendors) and then cuts the splines, axle flange, and grinds the bearing surface all after heat treat. Superior rolls the splines which is stronger then cutting them and does much of the work before heat treat which will leave the hardening thicker.

This thread has some good info in it
http://pirate4x4.com/forum/showthread.php?t=139095