Is there much change in drive ability with ported headers?

I've a Harvey Smith up pipe to put on, so just wondering if its worth the effort to gasket match the exhaust headers while im at it?

The car will be mapped after also.

 

Marginal gains. But saying that, add a series of marginal gains and you get a significant improvement. I did mine with a view that every little helps and it only cost me my time to do.

 

total different from simple port matching compared to actual gas flowing / porting............

 

I ported the stock headers and fitted a Harvey uppipe on my previous hawk sti at the same time. pleased to say the two did make the turbo spool earlier in the rpm range. Worth it for the effort iand relative low cost I'd say. Ideally you need an air powered grinder, but it can be done with a plug in drill too.

Worth tgv deleting too.

 

re the die grinder, i used this one
It's not particularly nice, but it was powerful enough with some decent carbide burrs, and also electrically powered (which isn't as nice as air, but at least doesn't need a big air compressor)