67 rear end

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dbenney
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Joined: 21 Sep 2018, 07:12

67 rear end

#1

Post by dbenney » 05 Oct 2018, 16:17

So after getting my Marti report I found it a lot about my car... A 67 true gt with power drum brakes, console, power steering 390, c6 work conventional 9 inch rear end with 3.00:1 ratio.

Here's my question. I'd like to convert to limited slip rear end but keep the stock housing and 3rd member.. is it cost effective to just replace internals? I'd also like something a little lower than 3.00:1... Maybe something in the 3.50:1 area... From looking a little the Ford 9 inch had 2 different spline counts... 31 and 28 for the axles.. is there a way to know what my car has without taking her apart and counting splines?

CATHOUSE
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Joined: 20 Aug 2013, 08:24

Re: 67 rear end

#2

Post by CATHOUSE » 05 Oct 2018, 21:22

Most likely you will have 28 spline axles. The 31s were usually in cars with a posi and gear ratios like 3:91 or 4:30. That usually put them in cars with a Boss 302, 428CJ or 429CJ. To be sure of what your car has you will need to see if the rear end tag is still in place. You will need to get under the car and look at the nuts that hold the center section in place. On one of those nuts, usually on the drivers side, there should be a small metal tag, about 3/4" X 2". There will be codes embossed into that tag. Those codes will tell you what you have. You could post a photo of the tag here, or just post what the codes are if you cannot find an online decoder and someone here will let you know what you have.

Randy Goodling
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cyclonelou
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Re: 67 rear end

#3

Post by cyclonelou » 05 Oct 2018, 22:34

Take a rear wheel off .
Look at the end of the axle at the spot the brake drum slides over.
28 spline=a large scallop right in the middle.
31 spline= 3 drilled holes visible.Either the center is larger than the outboard holes or opposite than that. Been so long I can't remember.There are 2 distinct sizes.You can't miss them.
I've got a Richmond Gear (USA) ring & pinion set for a 9". Used, yet perfect. I run 2.75's.$100.00 plus shipping. My price includes correct packaging.

cyclonelou
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Re: 67 rear end

#4

Post by cyclonelou » 06 Oct 2018, 09:55

I should've said take a rear wheel off if you have a center cap that bolts on from the inside.Otherwise just take off the hubcap/centercap.

dbenney
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Joined: 21 Sep 2018, 07:12

Re: 67 rear end

#5

Post by dbenney » 07 Oct 2018, 10:57

Thanks for the info guys!

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Royce
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Location: Dallas, TX

Re: 67 rear end

#6

Post by Royce » 07 Oct 2018, 11:39

Mercury didn't use any 31 spline axles in 1967. Unless something has been swapped out it should have 28 spline axles. They are easy to twist if you have a 390 and good traction. It might be time to think about where you want to end up before spending money on a Detroit Locker. It costs the same for the 28 spline version as the 31 spline version. The difference is the strength of the axles.
1968 GT-E XR-7 W code 427 Augusta Green / Saddle
1968 XR-7 R code 428CJ Ram Air Red / Black
1910 Model T Ford Touring Red / Black
1914 Model T Touring Maroon / Black
1915 Model T Ford Touring Black / Black
1917 Model T Ford Torpedo Runabout Green / Black
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