You can probobly suck up the slack withe the adjusters but the problem will be the track pitch.
The M7 is a 3" pitch and your MC may be 2.52"
If the adjusters don't allow enough then you can move the whole suspension back by drilling 4 holes in the tunnel wher the skid bolts in
I don't know how accurate this is but I heard if you run 8 inch wheels you can get away with running a couple inch longer track. I personally have never done this, but I thought I heard it somehwere. Just a thought maybe worth looking into.
Unless there is a prob with your 151 why change? Think about how lil your changing what hits the snow, 151 to 153? That isnt even worth the effort of the work you have to do. I personally think you wouldnt even notice an improvment in the powder. but thats just an opinion...