First, let's substitute b=8 into the equation (12b+25)/11:

(12(8) + 25) / 11
(96 + 25) / 11
121 / 11
11

Now substitute a=3(11) into the equation 8(5a + 17):

8(5(3(11)) + 17)
8(5(33) + 17)
8(165 + 17)
8(182)
1456

Therefore, the value of 8(5a + 17) when a=3(12b+25)/11 and b=8 is 1456.