Greasyman

It was easy enough to remove the UIM, but when I replace it, it won't sit flush against the lower manifold, there is about a 1/8" gap, enough to see the orange gaskets. I tried several times, looked for anything that might be interfering and made sure the locating pins were in the holes, though it's hard to see a couple of those. Maybe I'm not pushing down hard enough onto it, but it seems like the kind of thing that should drop into place with little resistance
Since it seemed I'd tried everything else, I was going to try tightening the bolts and drawing the manifold into place, but I'm hesitant to do that, because that's how you break stuff. Anyone else ever have this problem? Any ideas? Thanks.