I will say my trickflows had some chips in a couple ports (could have been cleaned without disassembly) and the valve spring heights were off by about .010-.015 which seems to be common. It was enough to put me on the edge of enough seat pressure with my cam so I shimmed a few up, oh and I did not like the shims they used so I bought some from pac springs with a smaller inner diameter for the guide bosses. I think it is pretty much established by now but no one should just bolt on a set of heads without checking them.