Hi new to the forums and just wanted some insight from someone whos done it or just a link on swapping a ej205 or ej207 into a 2nd gen legacy gt and what all had to be done to do that. I bought this car for 600 dollars and it has pretty bad rod knock once it gets around 3000 rpm so I was thinking that it would be a cool project just to take the old engine out and put in the wrx engine if it isnt a huge pain thanks!

That is quite a job. What year wrx motor and what year gt

in addition to help here, you might research at nasioc.com too.