Looking into this for an intake manifold. I was wondering if this can be done effictivly without taking it to a machine shop. I am looking for some good tips on methods and techniques as well as tools and/or bits to use in this procedure. I would attempt this on a dummy manifold so as not tos crew my stock good one. Are methods the same with dual runner as well as single runner? Any info would be helpful. I will not take this to a shop because I would rather try this myself.

*searched*

 

From what I understand, as long as the porting is smooth, and the casting marks are ground down, then its ok.

Its also important to make sure that both entries are matched so bottlenecking doesn't occur, and slow the air flow.