I was one of the first to mount a plow on the 450i as it was just new on the market, but now I believe there are mfgrs that know have a mount to fit midframe. I used a 1/4" wall angle iron x 1 1/2" and ran two pieces front to back connecting the three cross braces together. My plow mount attaches to those two pcs of angle iron. In order to utilize the quick attach and release feature the mount must hang below the skid plate and it is about 1 1/4" thick but when plow season is done I remove the mount (6 bolts) and the bottom of the machine is smooth again. I also replace those 6 bolts to help support the skid plate. Those two pcs of angle give additional support and protection to the bottom of the machine. If you do a search on front mounted snow plows for UTV's and atv's you will read some ugly stories about people damaging the front end of their machines but doing heavy plowing. I decided to not take that chance, always have used a mid mounted plow on my atv for 16 yrs and never had an issue, didn't want to start now....
