Does anyone know if there is much difference between the RRR type narrow headers and the previous type of wider ones, I have the narrow ones on my RRR and was wondering if changing would give better power or not.

From my limited experience I found the best headers are the original slimmer pipes. Although I only ever had a set of fatter (same diameter as early pipes) stainless type. The worst purchase I ever made. I now have two sets, one half stainless and one OEM. I'm sure the R model needs the extra back pressure the slimmer pipes offer with the more open stainless link pipe added is the best combo.