Thanks for sharing. Is the difference in price driven mostly by how much harder cast iron is to work? Seems like the aluminum heads would be a no brainer at that price point.
It is different because cast iron is harder to work, is a much worse place to start from and has greater core inconsistencies.
Now days, why would anyone buy RPM heads for (currently) $1,461.00 and then have them worked on to the tune of $1,750 for a total of $3,211, plus shipping, valve springs, retainers and locks set up for your cam? You can buy a pair of Trick Flow 240 for $1999.00-$2,199.00 fully assembled with the proper springs, retainers and locks.
