Why a 396? 454s are much more common and probably cheaper to build. Oh, and they make more torque!
I can see choosing a 427 just for the cache associated with the number, but if I were replacing my 454 my first choice would be a 572 for the added umph. If the budget would stretch that far...
If you are still motor shopping another interesting alternative might be the 348 or 409 Chevy. You might be able to persuade someone those motors were an option on NAPCO equipped trucks.
