I was thinking about a father son project of rebuilding a EJ25 engine to be a monster and to eventually put into my car with all the goodies that come along with a truly well built motor. I have not decided whether to stay at 2.5L or do a stroker to 2.6 L. Knowing the difference between the EJ255 and EJ257 are the heads, I am trying to decide on whether to by a used long block and rebuild it with performance parts or should I start with just a fresh block and build from there. Both options will in the end yield the same result, but I am looking for some real world advice from the board. If I buy a used motor I would like to buy a STI motor or EJ257 mostly because I like the center intake manifold and throttlebody, but have read about the problems exchanging the intake manifolds on a WRX for a STI intake manifold. So to bypass the problem looking at buying the entire engine. Am I going to run into wire harness problems, does not seem so, but I am not sure. I just feel this would be a great project that would teach my son tons about how a car runs, pretty much the same way me and my father built, muscle cars when I was younger. Any advice would be greatly appreciated.