Was about 18 months ago that i bought some from Classic Veedub for $500 a pop. Apparently the AMC heads that are available are neither 2L or 1800 sized but are in between. I honestly don't know but they've been a good thing. Some people say that the valves that come with them are shit and get new valves and stems fitted straight away while others talkabout how good they are.
In my experience, all good. Just when I was buying, George at Classic Veedub was the cheapest for the same part the others were offering.