Port Matching

[Topcat]

I was preparing to port match my heads to my intake manifold recently. When I got the heads back, I brought em over to my friend who is very knowledgable about perf just for another opinion. He said I didn't really need it and if I did do it, I would only gain maybe 5-10 HP. So with that, I decided not to.

I saved this so it may be useful for others here.

Just be sure to leave the intake ports  a tad bit smaller than the head ports, and trim the gaskets.
 
http://www.nmbuilder.com/Port-Matching.html

[moper]

I dont believe in many stock type builds that it makes much difference, mainly because most of those builds will never make full use of a port. However, once there is enough camshaft to make use of the whole port, you must at least look at them. Attached is a pic of an OOTB Weiand intake. You can see just with basic port matching the intake port to head transition becomes MUCH better. Yes, the intake can be left smaller than the head rather than risking the head being smaller than the intake and there being a step. But the top of the port is where 75% of the air moves. So a 1/4" step will imsply cause the air to be turbulent as it enters the head port. That would hurt this engines output ans certainly the wet flow characteristics of this particular package. Needless to say, part of my head prep for every build is a gasket matching of the intake being used, and I'm sure it's worth more than 10hp, and probably a bit in terms of gas milage.

[moper]

Same intake, after gasket matching. Note the step I left on the top.. Less than 1/2 what it was, and the ports are full width and shaped properly rather than left oval and uneven.