I'm with "JSeery" on this. Also, it's about the "theme" of the car; since the O/P already has dual carbs, it's obvious he is leaning more to the modified look rather than strictly stock. I think dual carbs on an aluminum aftermarket manifold looks better with a set of nice finned aluminum heads than some grungy old iron units. I also don't think you can completely discount a noticeable performance increase if the heads are prepped properly (per "Lawrie") before installation and not just thrown on. Optimizing the "squish" helps a lot, especially compared to a set of stock heads and you see an appreciable compression gain. It's a win-win deal (except for the initial cost).
I prefer composite gaskets, as I have never experienced a problem (when the heads were installed properly), and I would like to eliminate any electrolysis problems due to dissimilar metals. Properly prepared and installed, they work just fine. There is one problem that I have run into with current aluminum heads, and that is that they have oversize bolt (or stud) holes to allow easy removal down the road. This allows them to move around on the block which could lead to problems. The late Gary "GOSFAST" always pinned his heads (like modern engines) to prevent this. This is difficult to do with and engine already in the car, and I have developed an alternative method :
https://www.fordbarn.com/forum/showt...ghlight=sleeve.