rims & tires sizing

[buster024]

My buddy has either an '04 or an '05 450, and we need recommendations on sizing. I put new rims & tires on my 400, but I don't know if the size is different for the 450's. We do mostly trail, no racing or track. 20x11x9???

[tltcracing]

the stock tire size and whell size is just fine. i think the rears are 20X10X5 and fronts are 19X5X5.