66 Barracuda Heads

I understand that even Magnum V-8 heads will fit, and I recall they are closed chamber w/ a small volume like the 273. I think they have the requisite bolt holes for your accessories. The 5.2L is 318 cu in, so the valves may clear the 273 bore w/o cutting reliefs. You would need a different intake manifold, but that could be the Magnum "beer keg" to give you poor-boy fuel injection if you get a fuel controller (an old Holley Pro-jection is cheap, but can be quirky). You can also get carburetor-type intakes for a Magnum. The one downside is that those heads tend to crack between the intake & exhaust, due to induction-hardening there.