How do they perform stock??
Keep in mind I have a 500 engine in a 08 450 chassis. It handles better than stock CR and KX500. I don't get very high on jumps, 3 ft. off the ground is a big jump for me.
What's your weight?
My standing weight is 245 add the gear I wear and the items I carry, a few tools, water in a camel back = combined weight of 300 pounds.
Riding ability?
Veteran C class, ride for fun, I was out run by a 16 year old girl on a KTM 300 in the woods. She came up behind me, I pulled over to let her by and then tried to keep up with her. After the second turn I never saw her again. I asked a KTM guy parked next to my truck about the "chick with the pony tail" and he said she races and she's fast.
Terrain?
Single track woods rider with a mix of rocky single track in the small mountains here in Oklahoma. I ride at organized dual sport meets, 07 KLR650, 04 street legal KX500 so I don't have much to compare with a KX450.
The issue I'm having is do I put in new seals and ride stock for a season. Or pop the $$ and have them resprung and valved to desert racing right off the bat.
I had my forks and shock revalved and resprung by Factory Connection in Muskogee OK. for my weight and riding style. One day service. Had a cracked plastic part that cost $158 from Kawasaki total with part was about $1100. Have not ridden the bike yet, still in the assembly process.
I hope be together this weekend for the first ride after taking the whole bike apart.
I would say install the seals and see how you like it if you are doing the work. If your having someone else doing the work it might be cheaper to do it all at one time. Unless your heavy like I am or money is not an issue, respring/revalve.