I think you are right about the manifold surface not being totally flat, Pat. I put a metal level over it yesterday and had Dan put a feeler gauge in various spots along it's length. Surprisingly, it was pretty flat except the feeler gauge (.002) would slip in in other spots than where I thought the low spot would be. I thought it would be low up on number 1 and 3 port, but it was low back in the middle, near number 5-7.

I will try the sandpaper/board deal tonight and will pick up a long board sheet of sandpaper today.

What sealant do you like? I've never had an intake machined, can local shops generally do it correctly?

Don