You own a 610 ? Is this what vehicle you are asking about, if so the VIN plate if it exists will be toe board passenger side. 610 is a US model built in Lansing only and fist letter of the vin will be an L . It replaced the 407 in Oakland plant Sept 23 1930 and has a W8A 4 cyl engine. Engine number will be passenger side of the engine at back under the manifold on a boss, probably four digits. What you refer to as 5 8 30 is the casting date of the head or the block, May 8 1930. Should be casting dates head and block.
How do you know its a 610 ? The 407 is also 4 cyl built Oakland plant and Leaside Ont. We didn't stop the 407 and it was produced into 1932 under Dominion Motors after Leaside became totally Canadian owned and operated Jan 14 1931 and name changed to Dominion Motors. If its a 407 the Oakland vin starts with a C alpha, if Leaside T 1930, A 1931, H 1932.
Where Are You From? Ottawa Ontario Canada
Do You own a car built by Durant? 1932 614 sedan made by Dominion Motors