rx789gtus

I am currently driving my 1989 GTUs with a compression problem, i have to clean the spark plugs every week in order to keep the thing running, so i figure i am going to try to replace the moter with a 13b street-ported twin turbo motor, then go to a single turbo and front mount any ideas and resources that anyone has would be appreciated. And what problems might i run into with going from a non-turbo to a turbo??????????