Oil filter housing

[anlauto]

Here is an original 1971 340, never appart

WOW interesting...there goes my theory 

[ScottSmith_Harms]

 I do not have a good reference original example of a 71 340 built at the Mound Road Michigan plant (the blue painted 71 340's GM340) a number of details varied from the Windsor plant engines (orange engines - GW340) so it is possible that the filter mounting details varied as well. I can't say.