Stop in for a cup of coffee

So I got my bellhousing bolted to the trans, man, I love the fit of the bell and block plate but the hardware they send is crap. Not even sure it’s grade 5 Allen head button screws with standard threads but the Allen key size is not SAE or Metric. 5/16 is too large, 1/4 is too loose none of my 96 piece metric Allen key set fit it. So I left them finger tight and I’ve ordered new grade 8 hardware from McMaster Carr.

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Chevy?