Vortec heads were actually used in Marine applications before the trucks. The first application I'm aware of is around '92 IIRC. Although many people want the truck style intake to keep the engine looking stock-ish and minimize the amount of changes to the truck, there are other marine intakes that can be found.
http://home.metrocast.net/~shannen/e...ineIntake1.JPG
http://home.metrocast.net/~shannen/e...ineIntake3.JPG
I picked these up years ago but there are other options today right out of aftermarket manufacturer's catalogs. Good thing, too. Anything that looks like a marine manifold usually fetches top dollar these days.