I have taken my exhaust manifold off for the extractors to go on, and there is alot of carbon build up around the manifold on the engine, is it worth cleaning all this off, and porting out the edges?
can this be done with engine ect still in car assembled?

haha i was just thinking this today. Was thinking about port matching to the extractor gasket

I would think cleaning it will be ok, but porting with the engine assembled, hmmm I wouldnt...

yeah one sliver of head metal into the chambers and it could be good bye rings and bore fooked.