One of the benefits of a 'New' cast head is the known mileage - ZERO. If you use your parts from your head you at least know the mileage on them too.
A rebuilt head has an unknown amount of mileage and is most likely damaged, albeit vacuum/pressure tested. Plus it is rebuilt with parts with unknown mileage. Rebuilt could mean recycled two, three or more times and populated with parts tossed into a bin/floor.
This is the 'New' cast head company: J&C Enterprises Cylinder Head, 1-800-266-5599
Member of the Dropped Valve Seat Club.
Replaced #4 Piston, Rings, Rod+Bearings, AERA Re-Manufactured Cylinder Head and a light Hone. Then CLEANED the hell out of everything.