frame numbers

[nv my 69]

I am looking to buy a bare truck frame, its a swb, quite certain its a GM,this frame is set up for leaf suspension, there are some numbers stamped on it,  T71524914 and 378301 on one rail and 378302 on the other rail. any ideas? I am trying to convert a '69 lwb GMC into a swb, and would rather like to keep the coil suspension.
Thanks
<+))))><

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378301 and 378302 on the other rails are Part Numbers.  There should be a VIN stamped on it somewhere close to  the first and second cab mounts.

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project