340 full gasket kits??
Steve, I think what's happened is, the gasket makers have reverted to the large port intake gaskets and the larger bore size head gaskets. All of them (except a couple) I've looked at since you've posted this come with only one set of intake gaskets. Those that came with two just appeared to have two different styles, but the port sizes appeared the same.
What I would do is buy the gaskets separately. It'll cost a little more, but that way, you can get for example the smallest possible bore size head gaskets that'll work for your 340 and the thinnest ones. That'll add a little more compression. You can also make sure you get the right port size intake gaskets. You used to be able to get specific gaskets for specific engines, but at some point the gasket companies decided to consolidate them.