Short version.
ECZ-G heads have to exhaust port sections that need to be pinned. (cracked) Machine shop says totally fixable, but thinks different heads would be preferrable.
I can't stomach having more heads cleaned to find out they're also bad. We're in it for $280 in cleaning already.

Machine shop has a set of ECZ-C heads built and ready to go for $950
I paid $150 for the ECZ-G heads empty, so we have to buy valves, springs, etc and have the seats done and milling, etc. I assume it'll be $700 at least for head work.
What would you do? We're not trying to just spend crazy money and just want fun and reliable.