I put a pair of TBI heads [1986-1995] on a 1976 SBC and had no problems with the intake ports lining up. You'll need a new set of centerbolt valve covers, and you will need to work on the two center bolt holes on each side of the intake manifold. If you screw in the bolts without the intake on, you can see the angle you need change on the manifold, then just use a gob of silicone around those bolts upon assembly.
I think what 38377k5 may have been thinking of with the 8 bolt intake and ports not matching, would be the later model vortec intakes.
If you put a rv cam in with the TBI heads, you should see a Big improvement in performance, at least I did.
Good luck
Bob