A couple suggestions that may help.
1. The grade of your gravel can be part of the problem. If you are using Number 2 crusher or stream bed (round stone) they will cause issues due to the size of the aggregate. I top my driveway with either #1 crusher run or with "Driveway Mix" which is a combo of #1 and crusher fines that really pack down and are too small to jam the clearances in the blower (usually...)
2. I find that early in the winter season (first few snowfalls), the blower will really dig in to the drive because the ground has not frozen. So I take great care when blowing, sometime I have to raise the blower on the hydraulics so the skids are off the ground.
3. The best tip I have is if you only get a few inches of snow (3-6 inches), I don't use the blower at all. I just drive the tractor up & down the drive, packing the snow to create a base. This will allow the drive to freeze & harden. Once that happens, I usually don't have any problems.
4 Finally, I set my skids using a 2x4. I lay it under the grading edge of the blower and then adjust the skids to that 1.5" height. Obviously, I don't try to get the blower to take the snow off all the way. You've got to leave a bit.
PS - some blower skids/shoes are too darn narrow and just dig in to your gravel. My old blower had that problem. I had my neighbor weld on larger skid plates to the shoes that were roughly 4" wide and 6" long. Bend the leading edge up at a 45 degree angle so they don't dig. That really worked and allowed the blower to float.
