my last bike was a Guzzi I modified.....
here is everything I did to it....It started as a 2002 California Stone....
2nd front caliper and rotor
master cylinder from Ducati Multistrada
headlight fairing from a Buell Blast
turnsignals from a Buell Blast
racetech gold valves adapted from a CBR900RR
fork springs (mid 90's GSXR750 ones fit)
Magura Kawasaki dirt bike handlebar clamps with risers added to mount ProTaper "Honda CR High' bend bars
CRG mirrors
raised the forktubes 1/2" in triple clamps to quicken steering
adjustable clutch lever off of Guzzi Daytona
powercommander
BMC airfilter
magnecore wires
Mistral mufflers
Stucchi crossover
corbin seat
front fender off of California Titanium model with paint custom mixed to match stock color (a matte finish metallic silver)
repainted side covers to remove stupid Stone logo
lowered rear fender and rolled it forward to lower it over the tire.
removed ugly ass stock brake light and used an old Triumph replica
added Wilburs shocks (2 weeks before I sold it. doh!)
took frame rails from an old Guzzi Convert, ground off all the floorboard mounts and made stubs and welded them on 6 inches further back from stock to move all the stock Stone footcontrols backwards. They looked like rearsets that would come form the factory.
changed the 8:33 rear drive to a 7:33 rear drive for better acceleration.
It was fun to ride, but I got tired off all the quirks (the fuel injection was never perfect and never would be) and the overall weight of the bike. It weighed to much to heft around on a 400 mile twisty day - really wore me out. It needed more power also. I sold it on a whim and picked up the Yamaha FZ6 that I love. Nice and light, good power, and perfect fuel injection., I can pass just about anything anywhere - with the Guzzi you had to pick spots and plan accordingly to let the motor build some power. The FZ6 does well at track days also, where the Guzzi was just so-so. I miss the sound and the look of the Guzzi, but that's about it. I can go 500+ miles on the Yamaha down all the twisty roads in a day and still feel fresh....
I'm looking for a Yamaha XS650 now to turn into a cafe bike or tracker to keep be busy over the winter....