Brushguard installation question

[Hog Hunter]

I bought a used factory brushguard for my 2004 H2. Two of the six bolts I was to receive were lost in shipping and I replaced the missing items with the same size bolts as the four I initially received. After attempting the install last night I have come to the conclusion that these are the wrong size bolts for the upper mounting brackets. I think these should be narrower to enable them to fit throught the upper mounting bracket. Assuming I am correct and this works out,(also, is the procedure to slip a spacer over the bolt on the upper mounting bracket?) it appears that the grill needs to be cut to fit over the brushguard support. Can someone please confirm?
Thanks