Yes, they have their own proprietary valve location requiring a unique valve relief. If you already have pistons, you can notch them, or I have AFR specific pistons available.AFR heads look cool, but I believe have a valve placements and angles - requiring a new valve relief configuration from the 2 common ones (SCJ/P51 and regular CJ)
I think the AFR intake manifold is also required - maybe other intakes could be modified?
Rocker arms? stud girdle available?
Someone in the know will know what is required to use the new AFR heads.