not an engine builder

[95rayburn]

So what is gasket matching and what does it do?

[50j]

If you're referring to the intake, it gives you a smoother transition from the intake runner in the manifold to the intake runner in the head. I do it because I feel better about it but it doesn't usually make much of a difference in power. Some people ruin intakes with poor gasket match jobs, so be careful. There are also times where it's been better to leave the intake a little bit smaller than the cylinder head port size.