The biggest advantage imo would be that you’re not starting out with a core that’s already been heat cycled 100,000 miles worth.

The down sides are, they’re supposed to be used with intake rockers that have more offset than std heads use, and they don’t have particularly good lower lift flow on the intake side, since there is no height on the short turn.

I found the exhaust port to be tough to get good numbers out of for the amount of work involved.

Imo, I didn’t like them as well as stock heads, but on a rather high effort type build where you really needed some extra volume....... they are a little bigger than a std head....... so that might pay off.

The “If it were me” answer is........ find someone who wants them...... and take whatever you get for them and apply it to new aluminum heads.