The Stovebolt Site Forums The Shop Area The HiPo Shop What rearend for open drive line conversion

I have a 48 chevy truck and was wondering what rearend works best for the open driveline conversion. Also what is the most economical route and should I just spend the money and order a custom built 9-inch that will bolt right in.

If you are like myself and trying to keep cost down but not performance while converting your Driveline from closed to open you might consider this method.
When converting my 51 pickup to open Driveline, I went to a Boneyard and found a GM rear differential from a 71 Olds. 272 gears for $100. Spent another $100 rebuilding and replacing bearings etc before install. I knew that if I wanted to change the ratio at a later date for other applications, I could easily buy a set of new gears to fit my new application.
My main goal was to keep the width as stock looking as possible.
So I cut a stick exactly the width of my stock rear end to use as an exact gauge before going to the Boneyard. Takes a lot of guesswork out of the equation. Hope this helps answer some of your questions.

Somewhere on here I saw a list of rear end widths...

cm

You didn't say what motor you are running. When my rear end went out I used a 72 Coupe de Ville rear end which had 3.08 gears. That proved to be a little tall for the 235 six that I was running at the time. To give you an idea, when I was going down the highway at 65 the speedo indicated about 40. If you already have a V8 you should be fine. I will know for sure in about 6 months once I get the 350 and 2.72 Camaro rear end in mine.

I think this is a good deal.

I will be running a 305 I have laying around. I am using a chassis engineering bolt on mustang 2 front suspension. I also have a 350 turbo tranny. I have a rearend that a friend gave me and he said it was from a camaro. I will have to replace the gears, bearings and do any other repair. I heard that a ford explorer rearend was a good choice and also the s-10 4 wheel drive rearend was a good choice. If I use the 350 tranny I do not want a gear over 3.08:1

The Camaro will work since both it and the old 48 rear are about 61" mounting flange to mounting flange. If you ordered you CE MII with the 4 3/4" bolt circle on the rotor then one spare will fit front and rear. The S10 4wd is a 6 lug and still too narrow without spacers or less wheel back spacing. Haven't used the later disc brake Explorer but the early ones had the 5.5" Ford PU bolt circle.

Is there something wrong with your current driveline?

My Sonoma 4wd is 5-lug.

cm

I have a 79 nova 2.73 n my 54/235/3100.

S10 are not 6 lug. They are 5 x 4.75. If you need a wider S10 diff, look for one from a ZR2 with the Wide Stance option. They use a narrowed rear axle from the full size truck with the 5 x 4.75 bolt pattern, It is wider than the standard S10 by about 2".

Something to think about.......I'm a fan of the mid-80's Camaro diffs from behind the 2.8L.....3.08 and 3.42 are the most common with the 62" mount to mount width and the 5 on 4-3/4" bolt pattern. One thing to note: the Camaro diff axle tubes are 2-1/2" diameter so you need to make some strap spacers if you want to use stock 3" u-bolts. Also the sway bar on the Camaro (rr) is a bolt-on with only two holes to be drilled in the frame for the control links. PROS: You can buy these for $100.00 CON: you aren't going to find junk yard rims that will give you the 4" backspacing for good fender fit.

I'm also running a Ford 8.8 in 3.73 drum trac-lok with a 60" mount to mount width. Most Explorers are 3.73's with 31 spline axles. 94's and older are drum brakes.....95 and up are discs. Another axle readily available for $100.00 but have the 5 on 4-1/2" bolt pattern. This would be a great R&P ratio if you were running a .72 T5 or a 700R4 in your vehicle. BTW...the axle tubes on the 8.8 are 3-1/4" dia so get the U-bolts, bottom plate and the emergency brake cables.

I've got pics and documentation of prepping the diffs for both the AD Chevy truck and my Hot Rod......save yourself some work and check them out in my Webshots albums.

Dave

He's right, I'm wrong on the lug bolt number but the S10 4wd rear IS still too narrow by an inch on each side if you run any tire size at all. You can use the Colorado/Canyon rear to keep 6 lugs.

I have an '84 Pontiac rear with 3.07's and a T-5 behind a full pressure 216. For me this combination has worked well. I do have a set of 3.33 gears that will fit this differential if needed but here in the flat lands it hasn't been a problem. I do like the 60 MPH cruise at less than 3,000 RPM's too.
Normbc9

i was also wondering which rear to go with in my 51 so i searched here and every where and found no straight up answer. seems camaro is the cheapest way to go. i went with a ford 9 inch from quick performance. they helped me figure out what to order. between them on the phone and me in the garage with the tape measure, frame and wheels. we figured it should be 61 inches from hub to hub including the width of your brakes ie drum or disc. we got this measurement from a few odd ball measurements i remembered from this forum ie frame width and center of fender to center of fender. with these measurements and the frame and mounted rim and tire we came up with 61 inches. this would change some with diffrent wheels so you should have mock up wheels when measuring. i mocked up with corvette rallys 15x8 with 235/75 rubber. being a stock wheel i should be able to fit an aftermarket wheel pretty easily when it comes to that time. any how QP set me up with their housing and axles for right around seven hundred shipped to my door. they even would have welded my purches on for me if i wanted. i then bought a used 9 inch rear for the center for a hundred. if you get the right used 9 inch ie 31 spline, posi and desired gears. you could have a very strong rear for way under a grand. you can get 31 spline axles shortened for under a 100 plus shipping. and you can get the same housing as me for 3 hundred plus shipping. that would have cut my total down by alot. the guys at quick performance were really i mean really good to deal with. seams they had the housing built and out the door before i even got off the phone with them. on top of that built me an affordable rear end to my specs and shipped it to me within a week or so. anyhow i hope this helps people figure out this old question. the best way is to measure at least twice and talk to people in the know. knowbody will answer this question straight up because there are to many factors. but its simple if you have the a tape measure, your truck and the wheel your going to use. set it up and measure it out the only way to go. then find a list of rears with their measurements and find which will work for you. in my case new was the only way to go.

Welcome to the Stovebolt,Mo. Thanks for sharing your experience. Say, you might want to drop over to the Welcome Centre for the guys who look there to see who is new?

I'm sure there are other bolters close by you. Good luck on your project.

what about a 12 rear from a 67-72 c-10? if u get rid of the c clips i hear they can handle loads of power.

dont know the measurements but the 67 to 72 long arm suspension is a really great suspension as far as ride and handling would be cool if you could incorporate that with the axle

Going with a hand made custom four link on my axle..and air