FWIW I have a late set with accessory holes going on my '73 Camaro. I'm using them because they're going on an engine my dad built, and he ported the heads himself... so more of a tribute build on the engine. Sentimental value, nothing more.
I don't know what's more sad The fact they aren't worth anything so it won't be long and you won't be able to get any even if you needed them. Or the fact that I used to be so in tune with this stuff and didn't know how the value had dropped out of them, kinda hurts the ego a bit. Lol
Almost every set I've seen were milled so many times that getting a manifold to fit is near impossible. Sunk valve seats are a big problem, too. The only ones worth anything are the 2.02 screw-in guide versions. The Fuelie heads were used on just about every engine imaginable back then.
Yup same thing with a lot of people holding on to sheetmetal because they want $2500 for a fender. It’s not going to be too long the aftermarket will have something equal to or better and nobody will want your old stuff.
I Have a set of 461X machined with screw in studs Large valves and a set of Power pack 896 small valves. They are sitting around too. That's for the one of these days thing. Sold my 64 Le Mans, but have a tri-power set up and a 389 block still loafing in the garage. Hope to clear it all out after I finish my Bathroom remodel project.