So I'm already on a 3 hole gasket so the thick one as head been skimmed lightly once before..Is it possible to skim again if needed...

 

On a fabia vrs....

 

cheers

Manuals will almost certainly say "no". If you know exactly what you're doing you might be able to enlarge the combustion chambers (but we're probably talking something like 0.5cc each) to keep the compression ratio inside limits.

 

If you know an "olde school" tuner such as Dave Walker of Practical Performance Car then he'll can talk you through the playing about with a burette full of light oil better than I can on the web.