Actually the exact thickness matters because when you did that you physically move the cylinder up so it changed your timing and it ran like crap now if you take a little bit of yamabond or something similar and just put a thin layer of like purple Permatex or some such hi temp gasket maker slap it together and if it was always Factory timing it will run like a bat out of hell but watch your cylinder temperature if the cylinder gets too hot you're too far advanced if your pipe gets too hot you're too retarded you'll find out that when your advanced you'll go faster but if you're retarded you'll go up hills better so you have to find a happy medium and don't fry your cylinder or get your pipe so hot it falls off because it melted