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68-72 frame - shock hole measurement

2K views 20 replies 5 participants last post by  lucifershammer 
#1 ·
Does anyone know the factory distance between the UPPER bolt holes for the shocks on the frame?

My frame it measures 31-1/8" or so. I bought a UMI cross brace and it doesn't fit, it's too short. UMI thinks my frame is wrong, so I want to get some actual data.

Thanks
 
#4 ·
Should be 33 3/4 center to center. (Rear shock holes 68-72) and 31” for 67 and down had that backwards 31 for the 68-72 and 33 3/4 for 67 and down
Did they send you the front brace that goes across the front sway bar that would be shorter I believe.
 

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#11 ·
Should be 33 3/4 center to center. (Rear shock holes 68-72) and 31” for 67 and down had that backwards 31 for the 68-72 and 33 3/4 for 67 and down
Did they send you the front brace that goes across the front sway bar that would be shorter I believe.
I'm not sure where you're getting that information but it is not on the diagram you posted.
 
#5 ·
Don’t know if photos are uploading
 

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#6 ·
What are the dimensions of the brace they sent you? How much too short is it?

I'm curious, as I bought one that I haven't installed yet (and it's not handy so I can't measure it right now) and now I'm concerned that mine won't fit...
 
#7 ·
Yeah UMI is full of it lol. That's now 3 measured 31-31.25"

Their cross brace measures 30 7/8" at the MAX adjustment width (one side has oval holes).

The center of the oval hole should measure 31" which would give a good 3/8" range in either direction. But not the case.
 
#8 ·
So in your case, you are off by about 1/4"? I.e. It needs to be 1/4" wider to fit properly?

Sounds like the brace is 1/8" too short for factory specs, and your frame is 1/8" wider than factory spec? Did I read this all correctly?

I'll have to wait and see how mine measures and fits. Given my good luck with UMI so far, I'm hopeful.
 
#9 ·
My guess is UMI will step up and make it right. 30 7/8 is really close but if yours is 30 1/8 that’s 1/4 inch off how’s the mounting is it slotted to allow for factory tolerance? Most after market parts are going to need a little finessing. A ratchet strap and bolting the bar down would get you into spec.
 
#13 ·
Seems like there is nothing they can do. They are saying they sell 1000's of these and my 2 examples were the only ones that were wrong. They were willing to take the bar back, but that didnt help me. I had to modify it.

Their design is a good idea, it just should be 31" to the center of the oval hole to allow for adjustment. On 68-72 frames at least.
 
#12 ·
#16 ·
The only dimension on that diagram that measures 33-3/4" is the sum of two 16-7/8" frame centerline to body mount center dimensions (circled in RED) located in front of the coil spring mount. My 1965 measures 33-3/4" from body mount to body mount at that location fwiw. If you have other information please post it up!
 

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#19 ·
Tonight I pulled out my entire rear end and suspension and started prepping to install all the new UMI parts.

The first thing I did was attempt to put in the UMI shock tower brace.

Mine was the right length and the holes lined up perfectly, and it would normally be an easy install.

But, I'm not putting it in right now for another reason - my car still has all the factory evaporation control lines coming from the gas tank, and also the fuel line and the vapor return line run right along the top of the shock towers in the rear where the shock tower brace would go, and I didn't want to tempt fate and try to move the lines out of the way and turn an easy rear suspension job into what would surely become a multi week long nightmare of replacing lines that would surely snap if I try bending them as much as they need to go to be out of the way, and then as everyone knows that would lead to a full frame off restoration because like potato chips, you can't just stop at one. :surprise:

So, for now, no shock tower brace for me right now (someday in the future when I have nothing better to do and feel like getting into that mess...) but just wanted to provide the feedback that in my case, it was all the right dimensions.
 
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