The hole at each end won't line up. Does it look like the manifold is somehow too long overall or does it look like it is too far back or too far forward?

It could also be the gasket holes are slightly different, compare the gaskets old to new or try dry fitting the intake.

Could get two longer bolts, cut the heads off, thread only those two into the end holes and try to install the manifold. This may allow you to see the problem.

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