Intake Manifold question

Hey guys, I am building a Chevy 350 to go into my 84 Chevy K10, and I'm having a problem getting the right intake manifold. I have a 77 block that's 30 over, with some 305 Camaro heads from 86-88 (de-coded in a book). I have a intake manifold that's supposed to fit a 350, but the center bolts will not line up to the center bolts on the heads, but the outer bolts do. Did Chevy produce a special intake during the late 80's that went on the Camaro's that had these heads? HELP.!

In the late 80's (87 or 88) GM started using TBI equipped motors. The heads and manifolds are different. It's easy to check. With the manifold off screw a bolt into the center holes. If they stick straight up instead of angleing towards the center of the motor the heads are TBI. These heads also use center bolt valve covers.

I've seen guys modify manifolds to work, but they're kind of a hash job. After market manifolds are available for a proper fit.