theirs no set power figures for mods on this motor cos everyone i know who has one,also has a totally different set of power figures..they respond very diferently.
theirs also nothing cheap you can do as it cost afair bit in head work to release the ppotential....a set of cams and headwork with a decent chip will gove a relibale 170bhp which i have now...thats your limit more or less before it gets expensive..
nothing short of throttle bodies are required for 200bhp..so you may just have to live with it im afraid matey.