Working on these '462 castings -late 61's.Someone spent $$$ on machine work for screw in studs (7/16) and pushrod guide plates and also opened up the valve spring 'pad' to allow 1.5 dia. springs.They came complete. They had long slot 1.6 rockers on the intake side & the pushrod hole has been slotted. I plan on running 1.6 ratio roller rockers,works out to .520 lift with this cam. Only gasket matching porting.