For those of you that have ported out your heads, did you match tot he exhaust manifold. The reason I ask is that most theory tells us that a small lip at the port is good for keeping down reversion into the combustion chamber. We don't run that much overlap on the stock cams, so will it really make any difference. If it will how much of a lip did you leave?

 

Normally (over here ), when the standard exhaust manifold is grounded out, it's made larger than the exhaust port for that reason.
So yup, suppose so!

 

When I've do this in the past (on 911's) I ground and blended the ports to match the gaskets and that was great!
Graham

 

MY old XFlow had a slight lip on one port (but I thought that was an error)

The new one Dad and I just fitted is a perfect match to all gaskets(and quite a bit bigger )

will see if I can post photo's