(63a^3b^4c^3 : 7ab^2c)^3

63^3 a^3*3 b^4*3 c^3*3 : 7^3 a^3 b^2*3 c^3
= 250047 a^9 b^12 c^9 : 343 a^3 b^6 c^3
= 250047/343 a^9-3 b^12-6 c^9-3
= 729 a^6 b^6 c^6