All of our cores are fully inspected, ultrasonically cleaned, glass-bead blasted, and shaft is bushed.  Any damaged threads are either tapped or we insert an EZlok thread insert.   SBC units are bored to 46mm and custom laser cut blades are installed. BBC units are bored to 54mm and custom laser cut blades are installed.   Proper blade angle is set to insure correct RPM.  A permanent red LocTite is used to secure blade screws.  We use a VHT chemical resistant paint to coat the throttle shaft, linkage and springs to help protect against corrosion.  All of our bored base units come with a custom laser cut base flange gasket based on the year and engine size.