rocket fuel
You should have this verified but the freon is probably HFC134.
5w30
R134a
look under the hood. there should be a label that tells what kind.
4L60-E
Obd ii
4L60E.
15 to 18mpg
If the Blazer is gasoline powered the antifreeze can be any kind that is for sale for gasoline powered vehicles.
It will be a 305 or a 350 fuel enjection engine ( TBI )
700 R4 if it is automatic. 2x2
The transmission in a 2000 Astro is a 4L60E.