15-31-137. Small business corporation and partnership credit for alternative fuel conversion. If equipment and labor costs incurred to convert a motor vehicle to operate on alternative fuel are claimed as a credit under 15-30-2320 by a small business corporation, as defined in 15-30-3301, or a partnership, the credit must be attributed to shareholders or partners using the same proportion used to report the corporation's or partnership's income or loss for Montana income tax purposes.