[JAHamilton]

I was told that this was a Ford 9" rearend, but I'm starting to think that I have been lied to about everything on the truck....

The casting number is: 3707306 GM 6

Bolt pattern is 5x4.75

Width is ~60" from outer hub to outer hub.

What did this come out of and what should I do with it? I would like to switch the gears out, but I'm not sure that's a good idea any more. When I thought it was a Ford 9" I thought it would be no problem. Also, the rear end is a little bit too narrow for the wheels and tires I have on the truck. I would prefer an axle length of ~65" from outer hub to outer hub. Any ideas on what I should start looking for if I decide to ditch this rearend? I'll try to give you more information when I'm thinking more clearly. It's getting late...

[rrmccabe]

Looks like an old GM rear end to me.

They changed to the rear cover in 65 I believe.

[JAHamilton]

I'm starting to agree with you. This has to be a GM rearend by the markings. All I could find when I googled the casting number was some discussion about Old Vette rearends.

Should I rebuild this rear end or should I go with another one? I would really prefer to get a 5x4.5 bolt patter with a width of around 65 inches or so. Is Ford the only thing I should be looking at? Thanks ahead of time for the great advice.

Josh

[rrmccabe]

I think the casting #s were the same on passenger and Corvettes. The stamping would show if it was a Corvette and probably the ratio.

I cant say if its better to get another rear end as I dont know what you are doing with it.

I would think if its a custom vehicle, you might as well get one that has the right width and adapt it.

Not sure you would want a ford unless you have special plans to cut it or race?

If its a street rod I would find one that fits, has the ratio you want (if you can) and has the same bolt pattern as your front spindles.

Once again, depends on what you are doing with it.

Rich

[JAHamilton]

This truck (1953 Chevy 3100) will end up being my daily driver. The truck will not be raced by any means. I'm not looking for much acceleration out of the truck. I just want it to cruise well and get better gas mileage. I am thinking of ratio around 3.0 to 2.73 or so. I have a stock 350 with a 350TH transmission.

I need it to have a bolt pattern of 5x4.5 and be around 65" wide. I see that the 1973-1986 Ford Van 3/4 ton had a wide enough rear end, but I wasn't sure if the bolt pattern would be 5x4.5.

I liked the Ford 9" due to the ability to rebuild it easily. Is another rearend going to meet these needs? Thanks for all the help.

Josh

[JAHamilton]

Another option would be for me to tubb out the rear. With that I could go with a rear end down to 60, but that doesn't help too much. I'll have to really sit down again and take some measurements and then head out to a junkyard and get some real world measurements of what migth work for me.

[Centerline]

The stock rear end on your truck was about 62" hub to hub. The mid 70's Camaro and Firebird rears are a perfect fit if you're thinking about switching.

If you're just going to drive this as a cruiser and not racing or anything like that you don't need a Ford 9". That would be huge overkill.

I have a Firebird 10 bolt rear in my '53 3100 and it has an early hemi for power so even if your rear is an older unit it's most likely strong enough to handle that little 350.

[DV8]

Why wouldn't a rear-end from a 83 Trans Am work. It measures 56" from backing plate to backing plate. I know it is a weaker 7.5" diff. but It's not going to be "raced" and it already has posi and disk brakes. I'm going through the same dilemma right now and can get this rear-end fairly cheap. I've called several "vendors" and have gotten conflicting info. Is there anyone out there that has a similar setup??

P.S Centerline...How did you get your firewall to look so clean?? Did you replace it or just fill the holes??

Mike in Denver CO.

[M&M CUSTOM]

Originally Posted by DV8

Why wouldn't a rear-end from a 83 Trans Am work. It measures 56" from backing plate to backing plate. I know it is a weaker 7.5" diff.

It may or may not work in your particular application, but in his the frame may need narrowwed and the bed floor and wheelwells sectioned, widened, and/or relocated, which is more work than necessary when something more suitable for his particular needs may be readily available.

The pic shows the cast part number which is a typical GM numbering, and the "GM" right next to it only more than confirms this.

From your post you are obviously looking for a different axle, and you are pretty much already sure what width you need, if I can find it I have a link to a list of a bunch of different axle widths and mounting point type and measurements too.

[DV8]

M&M Custom. Thanks for your reply, I would appreciate any info I could get. I have alrady been to the www.chevytrucks.org website and they have no listing for my questions. I hope you can shed some more light.

mike

[xntrik]

Geez guys, come on....

Obviously it is a GM rear end.
Obviously it is a drop pumpkin style like the Fords.
It probably has 9 bolts on the pumpkin (not 10 like Ford).
With the 5 x 4 3/4 pattern it could be from a mid 50s car but since it is 60 wide, it might be an early 60s car (or a pickup changed to 5 lugs). Chevys weren't that wide. Pontiac was 6o wide I think.

I understand why Chevy guys don't recognize it. Nobody uses it because the Ford 8 + 9, and GM 10 bolt are so much better.

a Ford Guy...
x

[DV8]

Well I found the needle in the haystack. I bought a rear out of a 78 Trans Am that is posi and disk brakes. It was a little more than I was looking to spend, but after shopping so long I couldnt pass it up. Can any one tell me what this code is all about?

5P0 GO29 '1

this is stamed on the right side axel on the front, is there any other place I should look for "stamped" number to help me out.

Mike