Classic industries radiator finally gave out

Ok guys well i suppose its time, ran her on sunday and of course the classic industries radiator appears to be leaking at the bottom tank on the drivers side. I guess not too bad for about 8 years old. Not pouring but enough to notice, guess its time to go aluminum. I contacted wizard cooling and they recommended to go with the 1.25” tubes over the 1” they told me anything at or over 400 hp they recommend the 1.25” tubes.

i have been using 50/50 conventional green coolant and they also recommended i use a corrosion inhibitor as well. Do i need to? Has anyone used a corrosion inhibitor?