The Stovebolt Site Forums The Shop Area The HiPo Shop REAR AXLE SWAP

I have a 3/4 ton, and would like to swap over to a 5 lug, rear axle with up to date brakes, any recomondations on what to look for and where to go to get it, and the cost, and what is all involved to swap it over, I am located in Southern California. Thanks.

year?

51

First the lecture... switching over to a 5 lug rearend will take the truck out of your truck. Car rear axles aren't rated for carrying 1500 lbs of load in addition to the vehicle. If you are making a cruiser out of your truck this isn't an issue. If however you are planning on loading it and/or towing, this is a problem.

Ok you knew that so moving on.

Updated brakes... are you talking about moving away from your "Huck" style brakes and upgrading to "bendix" style brakes? or are you looking for disc brakes?

Many rear ends may fit your bill. None will simply drop in, so some cutting, grinding and welding is to be expected for putting a rear end in your truck.

It's hard to give you a specefic answer as to what to look for... 5 lug rear? What lug configuration? Are you matching the front?

I suspect you may be putting a MII suspension in the front, or swapping out your 3/4 ton axle for a 1/2 ton axle.

There is lots of information about swapping rearends. Don't get frustrated if you don't get a direct answer. More detail on your project will give us a better chance to answer your question, and give you more relavant answers.

Thanks for your reply, I appreciate it. I did swap out the original front axle to an original 1/2 ton front axle, I bought a 5 lug disc brake kit for the front axle and would like to match the same 5 lug patten with drum or disc brakes on the rear axle. I just want a crusier, to go down the freeway at normal freeway speeds safely, and run the original 6 banger engine at low RPM's I hope this info helps. Thanks again.

OK, so you are looking for 5 on 4 3/4 (small chevy pattern) Many have used Camaro rears before. I don't know the years however. I would think with a 216 engine, you wouldn't want gears much higher than 3.55:1.

The width of the axle you use will also be determined by the wheels and tires you use. 61-62 inches wheel to wheel is a good starting point. You can figure that there is probably room for about 10.5 inches of tire under the fenders on each side. The bed is typically 50.5 inches wide + 11-12 inches per fender. Typically you will be looking at a width of 72-74 inches to try and stay inside of. Lets assume you are using 15 X 7 inch wheels with 4 inches of backspacing, and a tire that is 10 inches wide... 62 inch wide rear Minus 10 (this equals the tire width) minus 1 ( this number takes into consideration the offset of the rims equals 51 inches. In this example, you would only have 1/4 inch of clearence for the tires and the bed sides. Using an 8 inch rim with the same backsppacing will stretch the clearance to 3/4 of an inch per side in this example.

Anyway, there are many different schools of thought for rearends. Many different ones have been used. If you do a search, you might find the widths of some of the common rearends that have been used before. Or you can take a tape measure to the boneyard and measure away. Do your own math, and take your own measurememnts, and it should be pretty clear which rear you will need.

so would a complete rear axle from a late model chevy Tahoe or 1/2 ton truck work?

Tahoe is a 6 lug axle, and is probably a little too wide. They have been used, but the wheels will likely sit outside the fenders. Perhaps a modern rim with a lot of backspacing can move those tires under the fender.

Just a suggestion, i put a 75 nova axle under my 57 half ton and its pretty much the same width as the original and has the 5 lug pattern. The only modifications i had to make were moving the spring perches. if your just wanting a cruiser something like that would probably work.

Another way.I took the axles out of my 55 2nd and took them to Moser Engineering in Portland,IN.Which is south of Fort Wayne,and darn close to the Ohio state line.They plugged the old six hole pattern and redrilled them for regular 5 bolt 4 and 3/4 inch bolt pattern.I now have all four corners with the 5 bolt pattern,which works out very well for me.

might not be possible to do with an 8 lug 3/4 ton rear.

51 3600 with 350 sbc and 700R4 tranny.

I bought a 81 Camaro 10 bolt with 2.73 gears on Ebay for $50. I had it rebuilt and swapped the 2.73 gears for 3.73. I also bought a 2002 Firebird rear disc brake set on Ebay. It bolts on to the 10 bolt axle.

gumbi what other years other than the 75 nova share the same rear axle...do you know?

a friend told me that an axle from a 91 ford van would work on my truck, any thoughts on that comment?

I used a 10 bolt from a 1969 camero and it has been fitting great. You will have to cut off and reweld spring perches. I also used the rearend conversion kit from cpp. the brackets keyed off the old rivet holes and went right in.

Im not real sure on all the years but i know that the camareo rearends and nova rearends were almost the same from like 67 to maybe 75. maybe some else will chime in and add on to this.

I used an '85 Borg Warner unit from a Firechicken .
Got me a posi and disc brakes as standard.
Fits a treat too.

Big Chevy/Jockbolter - Whats the WMS to WMS with your set ups?

and which IFS did you pair up with?

Moondoggie, you'll need to bear with me,I can't remember.

It's 7am here and I'm off to work,but i'll be in the garage tonight and measure it for you.
The 'basic' IFS came from Speedway and the Airbag kit came from Air-Ride Technologies.
I also 'upgraded' with urethane bushes,power rack and lowered spindles.

If I were to do it again I would personally import one with tubular arms myself,as I used a vendor here in the UK and I was pretty costly.
Another consideration would be our very own fellow 'bolter Scott Danforths GM based IFS,i've heard nothing but good things about it.

I could have had a higher spec set-up for the same money that I spent,not that there's anything wrong with the one I have.
The tubular set up IMO is just tidier and looks better.

Something i would have considered if i had my time back is the tire and rim look i wanted, I used a 1981 monte carlo rearend it is about 54-55''wide from backing plate to backing plate, just a little narrow for my 54 Panel, but the price was right at the time. I may use spacers to bring the wheels out a little closer to the fender edge.But if you have tires and rims already or a certin look your going for do some measuring up and that may help decide on wich rearend to go with.
Good luck.

THANKS jb...I like that rear end set up you have there..making moves to install the same

Check into S10 4wd,specifically,truck,not blazer. The S10 blazer 4wd is narrower,than the truck(my experience. Also with the S10,parts are more available. Some S10,have anywhere from 3:08,3:42,3:73 gear ratio.I picked up one at the junkyard,with 3:73ratio,positrac.I have an overdrive transmission,which is alright for my application,with 350engine.The width of S10 blazer is only 59inches,which I should have went with the S10 4wd truck which 60to61inches wide. Watch the back spacing on the wheels,mine 4and1/2 back space. That is the way I went,I could have gotten another rearend,but for 50 dollars,for a positrac rearend,I went with 1.5 aluminum spacers to make up the width difference. Good Luck