Can you do this at home? Is there a specific tool that you can buy to accomplish this? I do have access to a milling machine and can operate it.

Thanks for any reply.

 

There's a special tool depending on the size you need. I've heard of people using a standard drill or drill press to machine them down but an accurate milling machine is the best thing to use. Depending on the head castings it's possible to hit a water jacket if opened up too much or cut down too far.

 

Try page 350 of online Comp catalog.

http://compcams.com/Technical/Catalo...3/HTML/350.asp