Classic/Antique Car Repair: 71-2 mustang engine I.D. tag codes, dear sirs, mustang engine

Question
Dear sirs I have a 73 mustang clone and am trying to identify the motor it is a K620 S G or the G could be a Q any help would be appreciated     JIM / Chicago Toys for Tots

Answer
Jim, the numbers that you provided me do not exactly match anything in my reference library. So, a few questions. Where did you get that ID number? If from a tag where was the tag located on the engine? If it was two lines of letters/numbers which ones were on the top line and the bottom line?
Brad