I see a recommendation periodically that someone get their intake or heads Extrude Honed.  This is a process where abrassive putty is forced through an intake to remove material.  It is VERY expensive (over $500 for an intake) and hardly worth the gains to be had compared to a good hand ported intake.  Who am I to say that?  Nobody really, just a guy who has been porting intakes for about 42 years - but nobody ever heard of me right?  Well, here is the opinion of a very highly repsected individual who happens to agree with that position.......



Extrude Hone's process does not allow for SELECTIVE removal of material from a port runner.  Below is a comparison of the same hand ported stock Ford intake runner #1 and the Extrude Honed same runner.  Notice that the cross section has been biased to the floor and that on the old gasket marks that the alignment with the head is off by more margin than the lower bolt holes will allow for proper alignment.......

 

How about runner #5?



That should give you a pretty good idea of the differences.  Another issue for me is how much material the process removes from an upper intake.  Ford upper intakes are not accessible for porting, so some think the EH process is a logical one.  I've seen several and taken pictures.  I have been surprised at how much casting flash is left in the runners at turns where restriction is higher and you'd think the process would remove more material - take a look at these upper runners........






Here are the results from using Extrude Hone to port heads............



I just wanted to present some real life examples and opinions on this process.  If you are going to consider Extrude Honing an intake or head, I wanted you to have a source of some real first hand experience and opinion.  It's your money...................