Waitaminit....What has a headgasket to do with ports? Unless you mean waterports?These heads are completely bolt-on.Interchangeable.
-What are you expecting from this swap?
-These heads work best in combination with supporting engine mods. On a stock engine I see very little advantage to bolting these on and if your engine suffers from a lack of cylinder pressure/ low compression ratio, they could easily be a drop in performance, or no increase whatsoever.
-These heads allow for deeper breathing with increased camshafting, which usually requires an increase of the Scr, which usually means new pistons, which means an overbore,usually,and deck machining, which leads to other machining.Then to support the deeper breathing, a new manifold and bigger carb, and of course headers and a free breathing exhaust system,and a high stall TC and gears. And then hours of tuning.And then the new power breaks stuff which leads to more expenses......... You see what I mean? To just bolt them on to your stock or LC teener/360, and expect anything at all would be disappointing.
BTW the 340 with its pop-up pistons requires different Eddies or different pistons.
I mention these things because the conversation is leading me to believe that you may be uninitiated(hope Im wrong) in these things, and Id hate to see you spend a lot of money on little to no gain, and then come back here and complain about it.The Eddies are a first step, and at the price offered are a very nice first step, but probably not for your DD.