[JesseK]

Of particular note in the rules, note the BUMPER PERIMETER definition, and that nothing may extends past the bumper perimeter, ever.

Then note the definition of BUMPER, and note the restrictions on what you may modify about a bumper -- only the length and how they attach to the robot.

Then also note the game rule that says no matter what, the bumpers must be the only things that make contact with another team's trailer, which can affect how wide an 'open' spot is.

If your bulldozer can fit within these and other rulebook design constraints, you shouldn't have a problem.