I am about to do a head install sometime this month and want to port my primaries in the meantime while the heads are off.
Anyone have any results?

 

definitely will only help. probably not much, but its worth doing if you have the headers off and you have a dremel tool. doesn't take much time at all.

 

It will help you out a little bit,Its not hard to do but its worth the extra time and effort.

 

I ported mine. I'm sure gains were minimal, if any. Look at porting as not adding HP, but maximing the flow to prevent losses.I believe the exhaust port on the head is 1-3/4".MAC advertises these as 1-3/4" headers (inside measurement).My set had a 1/8" weld bead going around the inside most of the primaries. That amounts to a 1-1/2" inside primary when measured.

 

ttt

Any dynos.