i have a 1968 ford truck with 76000 org. miles it has a 360 which is running good but i want 400-450 hp and have ben told the 360 is not a real "performance" engine my dad has a 390 with close to 450 hp and he wont give it to me i also have a friend who has a rebuilt 352 that he says usually makes the same power the 390 makes . so should i build the 360 , swap in the 352 or wait till i find a good 390 ( i have a holly 600cfm 4barrel and a edlebrock performer 390 intake manifold.)