h22a swap in a 91 prelude

ok i'm never seen or done a 91 prelude swap.my friend keeps tellin me its a direct swap.but what i wanna kno is there any difference in the year,does it have to be obd1 or obd2,any wiring required?can i use the ecu that the prelude came with or do i have to get another one?please help this is the first time i'm attempting to do this.yes i have help with someone who does motor swaps.