I don't have time to dig up all your answers right now, but I'll start with this much, and I have documentation.
The first Detroit diesels were sold in April of 1938, only 3, 4, and 6-71 engines.
1938 Detroit engines (same as above) were sold to General motors Truck and Coach Division, as well as Gray Marine. in 1939 Allis Chalmers was a customer.
1949 introduction of 6-110 engines, and 51 series. (never automotive use that I know of, except two experimental trucks with 6-110 engines.)
December 1958 introduction of 53 series, in line 2, 3, 4, and V6.
Also introduction of V71 series, 6, 8, 12, 16.
in the early years Detroits were only available in GMC trucks, not Chevy. Best I can tell not in Chevy's until the 60's
I believe V71 Detroit's were offered in trucks very early, perhaps as early as 59, they would be 6V71 and 8V71. 12V71's were not in trucks until later on.
Hope this helps,
Grigg
