It would be 8376 because the numbers run from 8000 thru 9499.
Sorry I don't have a key with that number. But a good locksmith can make one from that number. GM used the same keyway groove style (Briggs and Stratton groove style 15) from 1935 to 1966. B & S B10 and B11 blanks, B10 is the octagon and B11 round.
If original, the door key should match the ignition key.
