I am going to replace the oil leaking intake manifold today. I never have done this before. Any tips or tricks? Its a TBI Chevy350.

I got it apart. Went to put the new gaskets and found that my new gaskets are not the same as the old ones.
The old gasket has the rear coolant passages open. The new ones have the rear coolant passages blocked, there is a small hole in the blocked part.
I hope this new gasket is correct. I don't know how enough coolant will get through the little holes.