Owner modifications to carburetor heat boxes are addressed within FAA guidelines under component repair regulations. These modifications must comply with applicable standards to ensure continued airworthiness and safety. The FAA provides specific instructions and limitations regarding repairs and alterations to carburetor heat boxes, emphasizing that any owner-produced parts or modifications should be performed in accordance with established procedures and regulatory requirements. This ensures that the carburetor heat system functions correctly and maintains the integrity of the aircraft's engine operation.