Aluminum heads and 63 vs 65cc chambers

rumblefish360 said
65 offers space for the positive deck piston height of the early 340’s.

Gotcha, that makes sense. Couldn't one just use a thicker head gasket in that case? It just seems weird to me that they'd take the time ($) to make two options if there's a readily available work around. I guess it's worth it to them.