71 front end alignment

I did a frame off on a 71 and since then it has not steered correctly.  It does not want to return to center very well.  When I aligned the front end it took more shims than what  thought was normal to get to the factory caster specs.  I know there are two different numbers for the upper left and right control arms, but I cannot visually see any difference and no numbers stamped into them.  Is it possible that I have them switched which may locate the upper ball joints further forward than normal requiring more shims in the front to push it back into alignment?
Thanks for any input.  

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Sorry,

coukd not open links to pics, but I did measure across to the mounting surfaces.  I was very close to 26 and 3/8.  Alignment was done ar full vehicle weight and after several jounces to settle everything.  I was able to get to factory settings, but the disparity between front shim packs and rear shim packs is what is puzzling me.  

Thanks for your input.  I will try going to the Speeddirect site again.  

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I got the links to function.  Must have been me.  Anyway, I have the A arms installed on the correct sides, so I will have to live with the shims I have installed.  I could install an offset cross shaft, but?  

thanks for the input  

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