ECM

i believe Detroit was the first electronic truck engine starting someitme in the late 1980's

 

detriot was the first electronic engine in the late 80's several other soon followed many i believe offered both electronic and mechanical options for a few years i believe into the early 90's i know cats and Mack engines both had a couple years that you had the option to order one or the other. you may have to look at a truck to determine electric vrs mechanical up till roughly mid 90's i don't recall exact exact years. but i would say by mid 90's most are probably electronic. with the first ecm trucks coming into the market somewhere around 1987. hopefully someone else will come along and give some more detailed information on the subject

 

93 94 for most you dont want that real early junk

 

What engine are you looking for? In that year range, my choice would be a 12.7 Detroit DDEC 3 or 4. 2nd choice would be a Cat 3406E or C15 (pre-Acert).