how far to port heads?

I've been told not to do a full port job on these heads like you would normally do 2a set of heads. Because these will actually lose power? I,ve been told to just basicly clean them up and do a little port and gaskette matching?

Interesting, where did you hear that.

Probably someone that didn't know what they were talking about.

The exhuast is definitely sensitive and you do not want to go into the floor. That could definitely hurt flow on the exhaust side.

The area directly below the seats is really bad. Just don't open the walls up any further the diameter of the seats. One of the members posted huge gains with a competition valve grind alone.

stempak said:

I've been told not to do a full port job on these heads like you would normally do 2a set of heads. Because these will actually lose power? I,ve been told to just basicly clean them up and do a little port and gaskette matching?

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how bout searching ?? this question has been asked many times before.

The biggest gains on these heads are the valve seats and immediate area on both sides of the seats. This is work that can be accomplished by a novice porter and a good machine shop. Oversize valves are also a big plus if the throats are opened up to match.

There are large gains to be had going further with your porting but it is not for the inexperienced or faint of heart. You really need a flow bench to do anything effective beyond that point.

Show the heads to your machine shop before doing any work. They can show you what to avoid and what to do. It is also helpful to have the seats rough cut before porting if you are going to use larger valves.