8. A four-digit number, all four digits are different, and the unit's digit is not 2, there are $\qquad$ such numbers.
8. 4088 If the first digit of this four-digit number is not 2, then the first digit has 8 choices, the unit digit has 8 choices, and the other two digits have 8 and 7 choices respectively, making a total of $8 \times 8 \times 8 \times 7=3584$.

If the first digit of this four-digit number is 2, then the unit digit has 9 choices, and the other two digits have 8 and 7 choices respectively, making a total of $9 \times$ $8 \times 7=504$.
Therefore, there are $3584+504=4088$ in total.