Interesting head mods, for sure.
In today's world, I guess it wouldn't be hard to design and build an all new head and intake (or use an adaptor like Jay's for available intakes).
Imagine:
-A SBF head with smaller Tunnel Port heads than the originals.
-A FE head (ala' Jay's plans) with raised HR type intakes and straightened out (or replaced 100%) and raised exhaust ports.
-a BBF with LS-7 (sorry!) intake ports.
Many possibilities here with new heads for 455 Buicks, Nailhead Buicks, BB Olds, etc. Maybe a great head for an old 500 CID Caddy too!
P.S. I'm aware that replacement aluminum heads are available for many engines, GM's included. Most are fairly close to OEM heads and not radical.