I have a 454 (445 casting #) truck block. Is there an aftermarket intake manifold that will fit this block for the idle to 5500 rpm range?
That 454 block is not a tall deck. You can get an intake from Edelbrock or any of the other major manufactures for that engine.
I forgot to include, for oval port heads. If my only option is retangular ports, then I will go that way.
You can get an Edelbrock Performer (idle-5000RPM) for oval port heads for about $175. new or even less used. They come up often on Ebay and at swap meets. I think they are about $175. new from Summit.
if it has the full oval ports (not the small peanut ports) then don't overlook the 1960s vintage factory 396 Qjet and Holley cast iron intakes...they work surprisingly well for moderate performance street use, and sometimes they're free or dirt cheap.