305 V6 Engine Question -- Intake Manifold

[Alaska_Ryan]

I have a 305 V6 in a 69 GMC 2500. Based on the model year, mine is the 305E model The intake manifold was cracked so I scrounged another from a junkyard and model year was pre-1967 since it had the eye brow lights on the hood.

I am having difficulty getting the intake manifold to seal properly. I can hear (and see) an exhaust leak coming from the manifold. It bolts down OK and the bolts thread but just not sealing right.

1) Any one out here think a pre-67 305 V6 intake manfold might not match up exactly with my 1969 V6 305? I know the earlier 305 V6s had a different model nomeclature. For example, perhaps the one I grabbed was a V6 305C.

2) Or am I just being sloppy in put the seal down and getting the bolts to thread?

[rsavage]

Did you clean the thread bolt holes on the heads using a bottoming tap so the bolts can draw down? You didn't change bolts to ones that are longer did you? Those are a couple of things I can think of as possibilities. Good luck.