56 Axle Swap Question

[Kartch1]

Sooo......I have done enough searching that my head is spinning. I currently am building a 56 Chevy. I am going with the Camaro clip on the front. I am looking for an axle for the rear and am not finding any good 70-81 10 bolt axles. I'm looking at other options with the following in mind:

- I'm doing a rear four link so spring pad locations make no difference.
- I would like a five bolt pattern but it doesn't need to be 5x4.75 like front.
- I would like to not have to order custom rims to make up slack in back spacing.
- Need something fairly strong without completely breaking the bank.
- Would like something I can readily find in a salvage yard.
- Will be running a 10" wheel. Would rather not tub if I don't need to.
- Plan on running a 17" wheel or larger.
- Rear disc is nice but have no issues running drums.

I know this is a tall order but wanted to see if you all had any ideas or suggestions. I may just need to be patient on finding an appropriate 10 bolt but everything I've seen so far is in bad shape or stupid expensive. Thanks in advance.

I will start a build thread soon I promise!

[Coupeguy2001]

Everyone is probably sick of this pic, but
72 GMC 12 bolt rear. bought for $100. I put new bearings and seals in it. Because it is 8 inches wider than stock, I had to use flat wheels.
Wheels are 96 Impala, 17X8.5. Tires are 255/50/17. tire total width: 10 inches. bought for $150 with used tires.
Lug pattern, 5 on 5. I used discs from speedway for the 5 on 5 front rotors ($65 ea with bearings and seals) but had to change the studs to use fine thread nuts.
I had to roll the rear fender lips with an aluminum baseball bat, and finish with paint sticks and C-clamps. Had to roll them 3/8"
rear Tires do not rub, and have 1/4" clearance.

[mongocanfly]

Nice truck coupeguy...would be hard to get sick of looking at that

[mongocanfly]

Kartch..have you considered narrowing a axle to get exactly what you need.?..a competent shop can narrow the axle housing and you can have the original axles resplined to fit fairly cheap..I put a 9in under my old monza that way for less than a hundred bucks..a long time ago

[Coupeguy2001]

thx Mongo
Making a case for white paint. aircraft paint. Been painted that color since 1977.

[svr]

Ford 9" from a pre '73 pickup is very close to your original '56, studs will be 5-5.5, ratios will usually be in the mid 3's, have one with 3.56 ratio, lots of after market support.

[mr48chev]

This is one of the go to flange to flange axle width charts that has been around for a while

That is wheel mount surface to wheel mount surface.

Trouble is some of those potential donors are in the "collector car" status. And the rears have gone up in price.

First you need to figure out the back spacing and width of wheel and tire and then figure out what width of axle you need. Other wise it is put the axle in and then match the rims to the axle and possibly end up with a look that is not what what you want even with the rim design you want.

Personally if you plan to run the big tires and plan to run the power I'd go with a nine inch Ford cut to width with the axles drilled for what ever bolt pattern I wanted. A bit spendy compared to buying one out of pick a part but the simplicity of changing gear ratios, the strength and the aftermarket support makes it a lot more viable.

[OrrieG]

Mr48 forgot the link. I think some guys have been using later model Ford Explorer rearends with discs and redrilling the axle flange to match the front lug nut pattern.

http://www.roadkillcustoms.com/hot-r...#axzz4gJZFMzyb

[dsraven]

here are some pics of my 57 gmc with the explorer 8.8 in the rear. brackets, 4 link bars and panhard bar are from welders series, modified at home. some other stuff is modified or home built because the air bag rear suspension is outside the frame. the ranger stabilizer bar fits with the explorer diff and could be upgraded to a heavier one from an upgraded sport series ranger. the shocks are s10 4x4 rears that I had kicking around for mock up but would work for suspension range with limiters for max extension depending on how you mount them on the frame. the frame mounts for the shocks have been reworked since the pics. the explorer diff is offset but there is also an 8.8 from a mustang with the center section centered. the explorer 8.8 is a 3.73 ratio, has disc brakes and large axles, posi and you can get parts cheap. an upgrade for powerful engines would be a stronger diff cover that has screw in bolts to keep some pressure on the carrier bearings. guys make noise about the c clip axles giving out but I have yet to see a failure or hear of a failure. have you ever seen any vehicle on the side of the road with the axle hanging out? if you did was it a lack of maintenance that caused the failure or an actual parts failure? there is an upgrade for that if worried about it.you can also see the axles that were drilled between the ford pattern to acomodate the chevy pattern. not that hard to do either. the track width is close to the stock 57. for more info try the ranger station site.

[bobinbc]

What size tire are you planning to run? I f you want it to fit right without spacers or surprises (narrowing) you need to know your wheel & tire size first.
You can play with rearend widths and wheel/tire sizes with this calculator to get an idea, you will have to measure and plug your numbers into it.
A 10 inch wheel with a tire that fits it is going to be fairly snug in a stepside BTW

http://tri-5.chevyrides.com/rear_tire.php

[Kartch1]

Thanks for the reply everyone. I am digging through your replies and there's some really good information. Just out of curiosity has anyone used an S10 rear axle with disc brakes and posi?

[Kartch1]

Originally Posted by bobinbc

What size tire are you planning to run?

I'm looking at a 10" wheel with something around a 285/50/18 Tire or something similiar in a 17" wheel.

[Kartch1]

Originally Posted by dsraven

here are some pics of my 57 gmc with the explorer 8.8 in the rear.

I'm looking at using the Welders Series kit as well. What modifications did you do to make it work? Would you recommend it?

Did you have any issues with the pumpkin offset with the Explorer axle?

[Kartch1]

Originally Posted by mongocanfly

Kartch..have you considered narrowing a axle to get exactly what you need.?..a competent shop can narrow the axle housing and you can have the original axles resplined to fit fairly cheap..I put a 9in under my old monza that way for less than a hundred bucks..a long time ago

I haven't looked into that option yet. I should probably ask around and see what shops are in the area. Anybody know any good shops in Southern Arizona that might be able to narrow an axle?

[Kartch1]

Originally Posted by Coupeguy2001

Everyone is probably sick of this pic, but
72 GMC 12 bolt rear. bought for $100. I put new bearings and seals in it. Because it is 8 inches wider than stock, I had to use flat wheels.
Wheels are 96 Impala, 17X8.5. Tires are 255/50/17. tire total width: 10 inches. bought for $150 with used tires.
Lug pattern, 5 on 5. I used discs from speedway for the 5 on 5 front rotors ($65 ea with bearings and seals) but had to change the studs to use fine thread nuts.
I had to roll the rear fender lips with an aluminum baseball bat, and finish with paint sticks and C-clamps. Had to roll them 3/8"
rear Tires do not rub, and have 1/4" clearance.

Not at all! Thanks for posting it. I am going to go with your rear tire size for sure. That's exactly what I am looking to do. That's crazy you were able to get an axle 8" wider than stock to work but it looks great!

[dsraven]

if you check the rite up on the ranger station site it talks about the offset and narrowing the explorer axle with another set pf short side axle tubes and axles. the tubes press out of the pumkin so you could easily have a shop do that for you if you don't wanna tackle it yourself. you would need the short side tube from another diff as well as the short side axle. some would say to weld the axle tube to the pumkin after. some would say buy a new short side axle because axles tend to break if they are run in reverse to what they have been running for years. they are not that spendy if you decided to go that way.
the welders series stuff I used worked well. the diff bracket is for a 4 link with air bags and fit good. the bracket for the front of the 4 link is a normal diff 4 link bracket-no air bag style-that i reshaped to use on the front. the flat steel L shaped frame bracket is home made and ground on the back side to fit over a bump in the frame, then a short piece of schedule 40 pipe, the same diameter as a diff tube so a diff bracket would fit up well, was welded to that frame bracket to accept the modified 4 link bracket. that keeps the 4 link tubes all parallel. the panhard bar was a welder series kit as well that I modified to fit my purposes. a lot of panhard bars are pretty short, which will make the diff move side to side as the suspension moves up and down due to the short radius of the bar. I went with a long bar to keep side to side diff movement at a minimum. the bracket on the diff was modified to put the attachment bolt parallel to the frame-fore to aft- so the bar eyelet would work as it was. the frame end bracket for the panhard bar was a home built unit fabbed from square tube and fit around the frame. it is not done yet and will require a link to connect the bar pivot point to the frame on the oposite side. this will keep the frame from twisting on hard corners which will, again, allow side to side movement of the diff.
the 4 link front attachment point location on the frame is a guess as far as an engineered 4 link is concerned. I went with a slightly upward angle from diff to frame with the bars to allow the bars to go to level then slightly downhill to the frame as the supension moves from full joince to fully extended.
the welders series site has all kinds of brackets and bars to buy as singles or pairs and they have kits to package the usual stuff together for better pricing. they are easy to deal with over the phone or via email.
pm me if you have more questions on what i did to my 57.

[Port&PolishMan]

Nice Work - the Brackets - those Look to be Water Jet Cut ? ( IN Picture Above )

Where Ya getting Those Puppies ?

Originally Posted by dsraven

here are some pics of my 57 gmc with the explorer 8.8 in the rear. brackets, 4 link bars and panhard bar are from welders series, modified at home. some other stuff is modified or home built because the air bag rear suspension is outside the frame. the ranger stabilizer bar fits with the explorer diff and could be upgraded to a heavier one from an upgraded sport series ranger. the shocks are s10 4x4 rears that I had kicking around for mock up but would work for suspension range with limiters for max extension depending on how you mount them on the frame. the frame mounts for the shocks have been reworked since the pics. the explorer diff is offset but there is also an 8.8 from a mustang with the center section centered. the explorer 8.8 is a 3.73 ratio, has disc brakes and large axles, posi and you can get parts cheap. an upgrade for powerful engines would be a stronger diff cover that has screw in bolts to keep some pressure on the carrier bearings. guys make noise about the c clip axles giving out but I have yet to see a failure or hear of a failure. have you ever seen any vehicle on the side of the road with the axle hanging out? if you did was it a lack of maintenance that caused the failure or an actual parts failure? there is an upgrade for that if worried about it.you can also see the axles that were drilled between the ford pattern to acomodate the chevy pattern. not that hard to do either. the track width is close to the stock 57. for more info try the ranger station site.

[dsraven]

the brackets are from welders series in Ontario Canada. they have a whole array of brackets and kits for different hotrod applications.

[dsraven]

here is the link for the welders series page. check it out. 4 link kits, panhard kits, frame mounts for 4 links, air bag plates, gussets, MII build kits, brackets , bars, bushings, etc etc.

[dsraven]

oh, sorry. forgot the actual link. try this.

https://www.welderseries.com/

[Port&PolishMan]

Nice - Work and Info - Thanks Bunch - Chief . .

[Coupeguy2001]

Also, I bought bar stock, and made rear shackles that were 1 1/2 inches longer than stock, and used 3" dropped springs in the rear that I got from the truck shop in Orange, CA.
Then I had to cut the axle bump stops down to 1/2 inch because there is no C notch.

[Kartch1]

For those of you who are know about the 8.8", how much offset does the axle have to the side. Is it enough that it would need to be corrected or can it be used as is?

[dsraven]

you could totally use it as is. the drive line angles from the offset will cancel each other out. just be sure to get the other drive line angles matched as well. usually a 3 deg down on the engine and a matching 3 deg up on the pinion, at ride height.

[Kartch1]

That's great to hear! I have found a few candidates that I'm looking at right now. Since I'm using larger width wheels in the back than then front I'm not worried about having the same lug pattern. I just wanted the same number of lugs. Thanks again for the info.