What engine will fit into a '85 porsche carrera other than the original?

I am planning on buying a '85 carrera but I want to swap the engine in case it causes problems. Other porsche engine preferably|||Any Porsche engine will fit into your Carrera. Are you familiar with the procedure for removing the passenger seat? Might wanna lay down some newspaper first, to keep fluids from dripping onto the carpet.|||yes ive converted at least 100 cars to date maybe you know me my namr is jack