The Stovebolt Site Forums The Shop Area Engine Shop Rear end swap

I have a rear end swap question that I hope someone can answer or know where the info might be. I am knew to vehicle restoration and I just bought my dream truck (aka rust bucket basket case) a couple of months ago. I have a 53 chevy with the closed drive and I want to swap out the rear end. I picked up a kit off of one of the memebers of this site that will seal the rear of my 4 speed trans for an open drive line. I measured from the inside of backing plate to backing plate and it is approximately 56 inches. Does anyone know what vehicles (i.e. nova, camero...) and what years of vehicles would have those dimensions for rear ends? Or someone may know where I can research to find this info.

Thank you all for helping a newbie.
Dan

You should be able to find information on this site.
http://50chevy.freeservers.com/

Thank you Houston 54. That was the type of information I was looking for. It appeared that measurements are taken from wheel mounting plate to plate or from the backing plate to backing plate. I think I have a lot of work ahead of me trying to find a good match.

i have a 79 nova and it fits nicely 60 1/2" over all (wheel mounting surface). the only draw back is the gear ratio 2.73 it works for me since i have upgraded the engine, dual carbs, dual exhaust and pertonix ing.. also i live on flatland. to change the ring and pinion is expensive, parts 200.00 labor about the same. RON

Dan,

Check with Joker on this site, I think he put an 84 full size Blazer rear under his AD...

I put a 1965 1/2 ton 12 bolt rear under mine. Fit great. It measured 61-1/2" wheel to wheel. I'ts got a 3.73 gear and 6 bolt pattern. I wanted the 6 bolt cause the rims I had were in good shape. There are some pics on My Site
Good luck

Bullnosebob: It kind of sounds like you guys might be finished talking so I thought it might be OK to jumb in here. I hope it's OK!

I noticed, Bob, on one of the pictures of your truck your shock mount.

Can I get a better look at that. It may be the stock set up for your truck, but it might also work for my 37. I hate to put you through the trouble, but if you have a picture of that, I would sure appreciate it!!

Also, what kind of shocks are you running?

Thanks,
Joe

If you dont mind a furd rear end look for an early 70's COugar 9" I put one in mine, 60 1/2" wheel mout to wheel mount. Worked out well.

I have a 70 camaro 10 bolt in our 53. Fits just fine with 15x8 inch wheels

I've got a '73 Chevelle wagon rear under my '55 1st. Fits like it was made for it. Or at least it did after cutting off the coil spring and control arm stuff and welding on spring pads.

I've got a GMC 270 with an SM420 4-speed. With 3.08 gears I can easily run 70+ and it is plenty quick leaving stop lights. However it won't do smokey burn-outs, and if you put a loaded trailer behind it you might wish for deeper gears.

You guys are provinding great information. It is nice to have a few options when I go looking for a rear end. When your looking for one specific item and a specific year it makes it difficult.

Any one with any other options please let me know.

Thanks agian guys, as always you all show why this is the greatest site on the web.

air ride technologies offers a kit to put a lincoln mark viii rear end in this truck. it has a 4 link set up and disc brakes. RON

Here's more pages with some measurements:
http://www.carnut.com/specs/rear.html
http://www.novaresource.org/axle.htm

I spent the afternoon putting a 10 bolt out of a 1979 Nova on my '52 today, although I didn't get it completely finished. The rear end measures 60.25" from wheel mounting surface to wheel mounting surface AND (big drum roll) the spring perches appear to be in the right places! This is with the stock springs swapped end to end to put the locating pins in the right place. This is a five lug rear, though, so if you're looking to keep all your wheel bolt patterns the same this rear wouldn't be a good choice.

While I have it bolted in right now I haven't put the bed back on to see how everthing looks and I haven't figured out what to do for lower shock mounts.

Is there any way to make a "sticky" post on converting your truck to an open rear? It seems to be a really common question and I think we all could put together a lot of good information.

A rear axle from a Task Force series will fit and it has a 3.70 ratio. They are somewhat older than what has been posted so far. They have the 6 lug axles.

Keahi,

I found a 1977 Nova rear end today and I may pick it up. Thanks for your info.

Oldblu49,
and Keahi,

You are the first to provide info on an older rear end that has a gear reatio and the 6 lug patern.

I have looked at all the pictures I have seen on the internet of AD trucks and it seems the hot rod trucks are almost all 5 bolt and the restored trucks are 6 bolt lugs.

My initial thought is to stick to 6 bolt. I don't know enough yet or have not researched on the available 5 or 6 bolt after market wheels.

I also don't know how hard it would be to find a Task Force series rear end for reasonable $.

Oldblu49, is the Task Force rear end the same width as the AD trucks?

Everyone,

Thanks for all the great info and reference sites, you are helping me make a better informed decision on what I am looking for and what I may want.

I am getting a good education on rear ends, vehicle rear ends that is.

Good info for a newbie.

Here is one more option. In my 46 1/2 ton I swapped out the center pumpkin for one from an open driveline 56 1/2 ton. I then welded in new solid type spring perches. It worked good for me because I kept my old housing and the e-brake stayed. I also kept 6 lug all around. The pumpkin has 3:38 gears. I'm running a 283 with a TH350 and it has held up fine so far.

If you do decide to go with the 1977 Nova rear look for one out of a Nova with a 350 and a 4 speed - according to one of those websites above that was the only combo that year that had 3.08 gears. Everything else was 2.56 or 2.73.

The 350/4speed cars also had a 8.5" ring gear which is much stronger than the 7.5" (and almost on par with the 12 bolt rear ends).

Keahi,

I also read the same info and I do want the 8.5 ring gear.

Rick,

Did you swap out the pumpkin or did you have it done? If you had it done, how much did it cost?

I am not sure it is a job for me. I have never worked on a rear end before and I would be better off paying someone to do the job.

Thanks again for new info and options.

Dan

Swapping out the pumpkin is not diffacult. It's a bolt in job. The hard part is welding the new spring perches and that's not too hard. There is no "setting up" the gears. They are set in the pumpkin assembly.

Rick, I have the same setup you mentioned above on my `54 1/2 ton. Except I was under the impression that the only gear choices were 4:11 (which mine is ) or 3:90 if your lucky! Where did you find a 3:38 third member? Was your donor truck an automatic? Are the `60 thru`64 trucks, "drop out" third members? Finding a "tall" 3rd member like that would solve a lot of problems for me! JD

iv got a caddy rear with disc brakes and monoleafs and lowering kit from obsolet chevy havent got the box on yet but it looks cool

I also don't know how hard it would be to find a Task Force series rear end for reasonable $.

Regarding this question....I recently picked up a complete 55 1/2 ton rear in good condition for $100, so they are out there.
Also...I think any 55 thru 69 1/2 ton rear will
work as far as width goes and will still have the 6 lug pattern.

So much good information! Imput overload, which way do I go? Cost...availabilty...easiest to swap out...least modifications...? At some point I will have to make a decision/commitment and just go for it.

In talking to some local junk yard dogs, if they don't have what your looking for they get on their yard web site and go looking for other yard dogs who may, but they can't seem to get a good answer on gearing. And you are relying on the guy on the other end to provide accurate info. I don't want to buy something and find out I now have to go through the work of getting the gearing changed! Any suggestion to this problem.

Does anyone have good measurements for truck rear ends for the 55-69 years?

JD 54, The 3.38 ratio was an option in '58-'59(maybe just '59) 1/2 ton trucks. The ring and pinion are being reproduced and are available from Patricks and several other vendors. There was also a 3.70 ratio option.

53fivewindow. I don't think there is any great difference in the width of the TF axle over yours. I just put mine in storage for a bit and cannot get to it easily so I can't measure it. As was mentioned above, probably the best way to do it is to swap the center section from one to the other. On the TF axle the spring pads are on top which would have to be changed. Swapping the center section everything else like the e-brake (as was stated) can stay but you have to weld up the hinge pins on the spring mount as you do not want the axle rotating on the spring like it does with the torque tube. The new rear u-joint will take care of that. If you did go to a 5 lug axle then you would have to change the front hubs mainly for appearance sake. you would also need to carry two spare tires. I like my 6 lug wheels.

Oldblu49,

Thanks for the info. I think I will try to hunt down a TF center pumpkin. I think the treasure hunt is part of the fun in rebuilding this truck.

Once again, all you truck guys are the greatest.

Dan

On the Task force rear axles, I believe the stock higher gear ratios where for trucks with automatic trannys. Hence their rarity. I have looked for one for years (not looking hard.) In my experience, almost everyone you will find will be a 3.90 gear ratio. They are out there at swap meets and yards. In the northwest I see them in for a low of $75.00 to a high of $200.00. The question I have is that everyone always talks about the axles under the TF trucks as only being used for the 55-59 TF trucks. Is this true? Or did GM use these same axles into later years?
Steve O

Nifty 50,

I will look for one for a while, but I have a 77 Nova 10 bolt 8.5 rear end lined up if I can't get the pumpkin. Either way I have lot of work and learning ahead of me. I look forward to the challenge.

If anyone knows Nifty 50's questions about years fot TF rear pumpkins I would like to know as well.

Thanks again for filling my knowledge cup a little more.

I think the TF dropout center section type rear axle was used through 1962. After that they went to a Dana/Spicer axle which does not have the dropout center section. The 4wd trucks started using the Dana/Spicer axles starting with the 1960 models.

I just picked up my 1977 6 lug 12 bolt rebuilt and 3.40 gearing. we cut the spring perches off and hope to find new ones. We have not mounted it to the 51 3100 but will soon
I guess we could make them but maybe someone knows who has them made??
thanks guys
hey JD there is a great rear end guy in rancho cordova. prentice enterprises.
gooday
jim

Jim, I got my spring perches,and U bolts from from Buffalo Enterprises in Washington. Give them a call (360) 652-7684 They`re pretty knowledgable about our old trucks. I think all they do is `50s stuff. JD

Seems like I saw something somewhere that pumpkins off of trucks from 36 to 72 were interchangable without too much modification.

I think that there was a warning to only use pumpkins off of the same sized truck, though.

I can't remember where I saw it. If I remember, I'll post the link.

I know zilch about 1/2-ton trucks. The 3/4 and 1-ton models are fairly interchangable '47-'72 (some models don't work, but a lot use the Eaton H0xx axle).

Most farm and fleet stores have perches in their "trailer parts" section.
Scott