Dmwhen you say ported RBC what do you mean?
In regards to customizing a IM, you want any changes done to one to be directly made for your build.
- TB section is ported or bored
- The plenum is taken off to shape the runners and bore the runners
- The IM is port matched to a specific head and gasket
If you want a professional to port and service a RBC or RRC, I can hook you up with quality work for a stellar price.