Tuning the xt600

[Valaar]

Hi,
When i went on my first ride with an xt600 i said to my self:Omg this bike pulls like a ****ing tracktor!
I got me one and soon after i realised that when the road
opens up the xt simply isnt up to the job. On the highway i can't keep up with the rest of the traffic and on my favourite twisty route i cant keep up with my friends.
I got a k&n filter and exchaust, raized the 2nd needle,but still there is not much going on,so im thinking about
changing the cam/big bore and rejetting.
There are pleny of big bore kits around but im afraid they only raize the midrange not the max-hp so the cams seems like the obvious choice,losing some mid-range i dont care.the bike has plenty.
has anyone tryed changing the cam,what was it like?
I also cant find dyno sheets on the net,anyone willing to share please reply,thanks!
P.s. I looked into the parts lists and found that the tt600e
has main jets #168/110 with 39hp and the same era xt has #130/100 with 36hp.Should i order tt neddles/jets?
P.s2.Forgot to mention there is a worhshop nearby offering oversize valves (for an unknown price).is that a good idea?