I just picked up 1995 300ex. It has these small mods:
Uni filter
aluminum exhaust
ceet seat cover
moose handlebars
pro track front tires
trail hawk rears
new honda red plastic
new bearings
I don't know what kind of muffler it has. It also has an aftermarket headpipe. The silencer is aluminum and says nothing and very short. It has a custom bracket and I don't think its made for a 300ex. I think its one of those cheap not a brand name ones out of Dennis Kirk. It looks like a Cobra but isn't loud enough. I love this quad. it handles soooooo good. The brakes suck all the way around. Every 300ex i've roda has had sucky brakes. Anyone else?

 

Congrats! Have fun! Nothing sweeter then getting a new machine

 

I took the front tires off and looked at the caliper and there is absolutely nothing left on the pads. The rear has a little but needs to be replaced too. I guess any brakes suck if there isn't any pad. The back disc has a little wobble in it so it probably goes thru pads fast.