At what point in modding an engine like ours, when is this an option? I know from days of building gassers that a good port job made a huge difference with the right combo of parts. Being that our PSD's are turbo charged, they need flow. How much metal is there to remove to increase flow. It seems to me that even a PSD with a good chip could stand to be ported. I can get a set of heads that are rebuilt for $400 and I have had Dick Landy do porting on my other engines and might give them a call to see if they are interested in porting a diesel head. This to me seems like a very worth while mod. What do you all think?