Computer numerical controlled machining?
 

Can someone please tell me more about CNC machine work for studs and if it's worth it for my next race engine

Large street port 2 rotor
Fully lightened and balanced
Borg Warner s360

I plan on using e85 whenever I can get my hands on some.

Also not sure what stud kit to go with

A good thread will be rolled into the material which is a forging process. The only company I can imagine making a stud kit would be ARP, and that's how they would do it. CNC equipment would only be able to cut the threads into the material, and that's not good because of built-in stress risers.

CNC is just a computer controlled mill or lather. Mill is generally for flat work. Lathes are for round.

Most studs are bought as ground round rod of a specific size and then cut to length. Then all is left is to roll the threads. This is the only "tricky" part. As this is not done on manual lathes. And can not be done on mills. CNC or manual.

There are quite a few studs on the market right now for the 13b. Oversized as well as OEM diameter. do a search in the drag racing section for engine studs. I am unsure if the studs available are rolled or cut. If you find out, please report back.