Got a free '70 Chevelle axle w/springs....now what?

[Oldgearz]

It's got 2.73 gears, which is great since I have a 3spd Muncie. I need to figure out how much of a pain this will be to put in place of the stock rear. Anyone know if anything's going to match up or do I need to swap all brackets from the stocker and cut all the mounts on the Chevelle rear? I think the springs will fit right in place of my stockers and lower the ride a couple inches just like I wanted.

[BR3W CITY]

10 bolt or 12 bolt? both came w 2.73's

[Oldgearz]

It's a 10 bolt. I think I answered my own question. Did a good compare and looks like nothing will work, will have to shave off and reweld my stuff over to it. I can't complain for getting the whole thing free w/the springs and brakes included.

[Captainfab]

Yep, you have some cutting and welding ahead of you. If you don't have the means to get good penetration on those brackets, don't be afraid of taking it to a professional. You really don't want the rear end coming loose. The Chevelle rear end will have the 5x 4-3/4" wheel bolt pattern. If you switch your front to disc brakes, the truck bolt pattern is 5x5". So you will need wheels with 2 different bolt patterns.

[bonacker]

If what you want to do is have a different ratio, the easiest way would be to change the gears in your existing axle. Far less work that adapting a different axle and no problems with different bolt patterns. Probably cost less to just change gears too.....

[Oldgearz]

I thought I remembered reading about what I could do w/the existing gmc rear end which is 3.90, and pretty much all that was available to do was switch to 3.38 which was an option on our trucks, I don't think anything smaller would work on it. I originally wanted 3.08's, but I'm willing to use the Chevelle rear. The 2.73's will give me better mpg on the freeway and interstate plus I can do 80 without high revs on the v6. What about getting 5x5 axles for the Chevelle rear?

[Captainfab]

If you are wanting higher gears than the 3.90's, I would just look for a '63-'70 truck 12 bolt with 3.08 gears. You will still have to move the trailing arm mounts to work on your '62, but it will be the correct width, and you can get the 5x5 lug conversion axles. The '71-'82 12 bolts will work, but they are 1.5" wider overall, and they already have the 5x5 lug pattern. However there will still be cutting and welding involved, but you will have a better differential IMO. I imagine the Chevelle axles and drums could be redrilled. Have you measured the Chevelle read end to see how the width compares? And don't measure backing plate to backing plate, that is not accurate. You need to measure WMS to WMS (wheel Mounting Surface).

[Oldgearz]

I haven't measured it, but from the way it looks, it's roughly the same or slightly wider by maybe 1/2 inch total. Now the other question that I have is if I stick w/the 5x4.75 pattern on the rear, can I do anything to my stock front 6 lugs to re-drill them to 5x4.75 without upgrading to discs? I'm trying not to spend alot of money on this

[Captainfab]

You can buy a front disc brake conversion that uses the original spindle, and will give you the 5 x 4.75 bolt pattern. I believe POL sells it. You could plug the 6 lug holes and redrill the hubs and drums to 5 x 4.75, but you would also have to have the center register of the hubs turned down to be able to fit a 5 x 4.75 wheel. By the time you do all of that you may as well upgrade to the front discs I mentioned above.

[markeb01]

You might want to take another look at your stock rear axle before making any change. Being a GMC it should be equipped with a Dana 44. These axles remain very popular with the 4x4 guys, and a wide selection of gear ratios remain available either used or new. A gear swap would be a lot less work than dealing with perches, width changes, 5/6 lug issues, e-brake connections, etc.

If you do decide to go with a passenger car rear end, CPP makes a kit to install 4 ¾” disc brakes up front:

http://www.classicperform.com/Instru...DF/6062DBK.pdf

[Oldgearz]

Well I'd love to swap out to different gears but I thought w/the '62 gmc rear I was limited to only the 3.38 optional, otherwise I had to change out everything? I'm not sure what my options are, can't find a good thread w/the info I need.

[markeb01]

My truck started life with a 3.92 gearset. Several years after swapping in a 350/350 and using it as a daily commuter, I had the rear gears swapped to either 3.07 or 3.08 (I don’t remember which). I had a 4x4 shop do this with used gears out of a Chevy Blazer. This required swapping to the “other” carrier since the break is at 3.73 & down (numerically) or 3.92 & higher. Yukon Gears lists a 2.73 gearset for the Dana 44 (p/n YG D44-273), so there are at least two high gear ratios available.

http://www.filthymotorsports.com/Yuk...fm-yukonrp.htm

Subsequently I went back to a manual 4 speed transmission and a 4.09 rear gearset, which again required swapping the carrier back to the 3.92 & up version.

The Dana 44 has a very distinctive cover making identification pretty easy, and there are tons of articles on the web providing more information than I’ll ever read. My suggestion is just to make sure what you have before thinking about getting rid of it.

http://www.offroaders.com/directory/axles/dana44.htm

http://en.wikipedia.org/wiki/Dana_44

http://currieenterprises.reachlocal....id=17881417062

[Captainfab]

Mark is right. You probably should verify just which differential you have. I was assuming you have the Eaton HO30, by what you were saying. However you could have the Dana 44, which has a lot of aftermarket support.