I recently bought a 1991 MR2 Turbo. however, I believe that the engine has been replace sometime before. b/c some of the parts that i have replaced after getting the car weren't 1991 parts, they were 1993 parts. How do I find out what year of the engine do I have? I know its a SW20.

Further more, I am trying to figure out rather I should get AFC, if so... which one should I go with? how about boost gauge, intake and exhaust? i want to get an intake, but not sure about exhaust. b/c...