whats needed for a top end rebuild? my turbo is starting to get a bit rattly on top, i know its had a bottem end rebuild so thats good, but what parts do i need for a top end rebuild? or should i just buy a top end thats allready been done? also which cam kit is the best to go for? my car is only mildly tuned and i dont want it to get too laggy, got a grs fron mounted intercooler, k&n, exhaust, bleed valve and its allready chipped but will probably rechip when i get the new head.