John
I did the same to mine a few months ago, hard work but amazing results. With mine I also had to remove the winch bumper and wiring, rear bumper, tank guard and +2 shocks from my old 200tdi. I bought new +2 progessive springs from Scorpion, -2 turrets, -2 rear shock mounts, dislocation cones extended brake lines and QT front and rear arms. The rear diff on the 300 was leaking and as I had new discs on the 200 we swapped the axles over aswell. This was done with the help of a good mate and his workshop. There are a few photos in my gallery which show the days events. A couple worth noting are the rear axle, nearside with -2 shock mount and offside with standard, you can clearly see the extra droop, and for everyone that asks about tyre sizes you can see how a 235/85 16 grizzly claw sits in a standard arch with a 2" lift, not a lot of room left hence the extended arches.
Gav