Here’s a little perspective.......

Think of all the aftermarket heads GMPP sells.

Think of all the crate engines GMPP sells.

Do you think they have a team of people “going through” their head assemblies before installing them on those crate engines?
And many of those crate engines are sealed engines for use in various oval track series.

Right out of the crate and into the race car.

There are several series in this area that use them. It’s pretty rare for them to ever have a problem with a cylinder head that isn’t owner induced(severely overheated).

It’s one thing to have the heads gone thru if you looking for a little more performance, and some modifications will be performed.

And you may even find a little thing or two you don’t love......... but it’s pretty rare to find something that would actually cause a “problem”.

Generally, if the spring package installed on whatever heads you’re looking at is suitable for the cam you’ll be using........it’s not crazy to use them ootb.

Through the years, I’ve seen the occasional “prepped” heads where I felt like they were likely better before the “prep”.

The fact is, not all machine shops produce top quality work....... that’s just the way it is.
So, depending on where you’re having the work done........ they may end up better than ootb....... then again, maybe they won’t.