I'm resealing a 1997 ej22. The coolant crossover pipe o rings are flat. Are the supposed to be like that or are should they have a curved mating surface and these should be replaced.

I had to service that pipe on my '92 this year and I replaced those O-rings while I was at it.  I am pretty sure they were round in cross section (like an O-Ring should be!) but to be brutally honest, my memory is shot and I don't clearly remember!  But the bottom line is, they are not expensive and my opinion is that this is one of those cases where you really should replace them "as long as you are in there".  You will kick yourself if they leak after you reassemble all that stuff.

They're supposed to be round. Definitely want to replace those because its alot of work to have to remove the manifold again just to fix a leak around one of those o-rings.