Be sure to check a couple of things...
1. If one is using pushrod with a bigger diameter than 5/16" you likely will have to mill out the hole for clearance.
2. If using a high lift cam (>0.500) one should check for valve spring windup
3. If using high ratio rockers be sure to check clearance for the rockers

Overall the heads look pretty good and the price is rite..
But if one is looking to put these into a hipo track car with certain exotic valve train components, it is strongly urged that a complete checkout be done by an experienced machinist for the above points..

Just my $0.02..