It will be a 305 or a 350 fuel enjection engine ( TBI )
look under the hood. there should be a label that tells what kind.
16 bolts on the trany oil pan is a 700r and 12 bolts on pan is a 400r
R134a
5w30
Should be a 700R4 Trans.
4L60-E
Obd ii
rocket fuel
4L60E.
15 to 18mpg
If the Blazer is gasoline powered the antifreeze can be any kind that is for sale for gasoline powered vehicles.
700 R4 if it is automatic. 2x2