Not at all.
I've just fitted a pair of these forks to my XC, and even with the WP's in standard trim it is a huge improvement.
I went the route of fitting a KTM front wheel and the yokes from an EXC ktm.
I just needed to get the stem on the yokes machine down to 28mm to take the standard bearings. You remove about 1mm in total, so nothing to worry about in the terms of integrity.
The other option is to press out the ktm stem and re-install the XC one in it's place. IIRC Timpo went this route.
To put these forks on my bike i needed:
Forks
Yokes
KTM front fender
KTM front wheel (complete with disc) and axle
calliper bracket- the XC calliper is the same as the KTM unit, it just needs the adaptor.
I have a ktm part number if you want it.
All that is needed then is to fabricate up support for the original dashboard, headlight and ignition switch.
If i was going this route again, i would search out some yokes from a 690 to go with the forks. These have the lock stops on them, unlike the exc one's i fitted which don't.
