Here's my solution to correct the forward tilt on the snowplow on my UForce 1000 with 30" tires, the additional height of which had made the shoes ineffective, causing the plow to dig into my gravel driveway and roads. This should work for any lifted or re-tired machine with these types of plows and frames.
1. Hook the plow up, set it down on a flat surface and loosen the springs.
2. Remove the two plow blocks (which maintain the rearward plow position) which are bolted to each side of the frame above the pivot bolts.
3. Manually tilt the plow back until the shoe shafts are vertical.
4. Place the block back on the frame and against the blade rib below the original hole. Make sure you have enough frame metal to accept the 3/8" hole, but the higher the better. Punch a center hole.
5. Drill a pilot hole with a small HSS bit, and then follow up with a 3/8" HSS.
6. Measure and repeat on the other side.
7. Bolt the blocks back on the new holes and tighten the springs up.