[SS427]

I have them done all the time. Typically costs me about $100 a pair and looks great when completed. It is not rocket science to a machinest and with a donor manifold and an asperator tube to show them, it is actually quite easy. Your engine builder should be able to do this. If I am not making the A.I.R. functional, I have them stop the hole short of going all the way. This way I do not need to block it myself. Make sure they chamfer the opening on the outside like the original as this is often missed.