Machined Heads

[sc6.0]

I am going to pull the heads from my truck tomorrow and they are going to be going to the machinist next week. I am going to have them Magnaflux tested, compression checked, and milled. But, my machinist has also recommended that I would benefit greatly from having the heads ported to match the exhaust manifold as well as the cylinder ports. He claims that this would free up much of the flow within the engine and that I can expect an increase of 15 to 40 horsepower. Can anyone verify this, and is it worth it? It makes good sense seemingly, but is it likely, or better yet, worth it?

[skanj0]

Personally I wouldn't bother with porting.

You are smart to have the heads checked rather than just changing the head gaskets and slapping the old heads back on.

[charlesrf600]

I dont know about the horse power claim but it is an old trick alot of guys to on gas mills. it just provides a smooth entry to the cylinder so there is no disruption in airflow getting there. could it help sure is in needed with our truck not really unless you are wanting make power from everything you have.

[PGreenSVT]

6.0 heads actually have terrible flow characteristics. Yes you can increase flow by porting but you reall need to port both intake and exhaust. Port matching which is what it appears your machinist is talking about will help some but is short of a real port job. With a real porting you might pick up 30hp. Or you could just add more boost.

[mil-specrestro]

It would be a waste to match them with porting. There are much greater restrictions inside the heads in both the intake and exhaust sides. These smaller passages are there to allow everything to fit where it currently is.

The intake also has several restrictions were the studs and egr are mounted. Another main source of flow problems is the casting flash and texture inside all the parts.

I would save the money and get a good tuner...probably less in time and money spent.

[mil-specrestro]

Don't forget that a good rebuild should include a valve angle grind and seals too.