I have 2001 subaru forster sohc... can I swap it to
the ej20 dohc turbo engine? If yes, is it a easy swap
No its not easy. The engine will bolt right up to the transmission but you will need a turbo crossmember. And you might have to change you lower control arms, sway bar, power steering rack, etc. And also if you have to replace the steering rack. Guess what. The splines are different. So you now need a new steering column or adapter. And also a lot of wiring to do also. If you don't know how to read the wiring diagrams. Better off paying Iwire services to do it for about $800+. The best way is to get a wrecked WRX or something and swap everything over. I would only suggest doing the swap if you know how to turn a wrench.