As mentioned earlier, if its an educational journey, than go for it, and if your hand is as steady as Dr Dwaynes (fast68plymouth), than there is definitely good hp to be had with port work. Personally, I would go the route of finding a set of already worked heads, preferably a closed chamber and aluminum if within the budget, because your compression is going to be really low (like 8-1 at best) with the 90cc 452. Or consider having them milled, and definitely use a shim gasket to help bump up the compression.