i need to get a aluminum manifold for a 1989 i have the heads with the center bolts are more in a up angle then the rest of the bolts i do not know what those heads are called and where is the best place to buy a manifold thanks.

 

Those are called the newer, 1987 and up style heads (with the center mount valve cover bolts). Summit and Jegs carries intakes for your engine. In a pinch, you can use a conventional intake manifold and alter the angle of the two center mounting bolt holes on each side.
Don't confuse your heads with Vortec heads, that's not what you have (unless a previous owner did an upgrade).