Looks great! Is it normal that a base stack doesn't have a flange to use to attach it? I don't have a base stack, just curious.

One thought - if there's a way to attach your base stack to the arch with screws or something, I wonder if that might be better, so you can re-use it if you wind up buying an evaporator next season or the one after. That stack will last forever, and it would be a shame to have to chop it up to move it to a new arch.

GO