Don't use a 450R shock...
a few reasons
1.) its like a racing shock, and it is stiff and has a stiff feel
2.) stiffer b/c the 450r is heavy heavy heavy
3.) its bad for your blaster b/c its almost like having no shock pretty much
4.) 400 ex shock is better.. but yet..it is still sorta stiff, so you can't even imagine a 450R shock...
5.) THIS IS A GOOD REASON TOO--- DON't DO IT B/C I SAID SO