Help! Intake manifold won't fit!

I always keep some of the later big block intake bolts around-the ones with the unthreaded nipples on the end. They are much easier to start, get all 12 started, then start replacing them with the small block bolts. I think the big block bolts are too long to run all the way in-they could run into the pushrods, I'm not sure. It looks like it might not work for you though.