BG, good point on the 350. Hadn't thought of that one and don't know specs on the weights.
I'm doubting that his wife is gonna like a pipe b/c of the noise. A 2r tip will tell him that since it's a lot louder to me than stock,but5 not near as loud as a pipe. I would say airbox mods, a new filter that flows better like the UNI and possibly jets or a dial-a-jet. I've never tried a dial-a-jet but you had one so you can confirm or deny it's abilities. I would think it easier to play with than to continuously pull the carb and jkets to re-jet but you can elaborate.
I took a Kodiak 450 weight tonight and popped the sleave off of it which decreased the weight by 2.5 grams. As stock, the weight, with sleave, is 14.1 grams. Without the sleave, it's 11.6 grams. As stock, the total weight on the Kodiak 450 weights (which I am assuming is the same weight they use in the Grizz450) is 112.8 grams for 8 of them.
If you cut the sleave from half (4) of the weights you drop to 102.8 grams. If you pull the sleaves from all 8 weights, you drop to 92.8, which is an 18% decrease in clutch weight total.
If you want to screw with weights and lower their overall weights like many have found good results on the 700s from doing, I would say first pull the sleave off of 4 and see how it goes. You could even do 2 of them first and put them opposite of one another to begin with.
Just a thought. If it were mine, I would take a chance of wasting 2 first. Then if I see a little something, do 4.
Keep in mind, we are not saying if you do this, you WILL have gains, as we've never messed with weights on a 450. It's just a suggestion on what you could try.