Brushcutters

Hey guys, so i just purchased a 98' year model 265RX clearing saw and i was wondering instead of using the T45X string trimmer attachment will a T55X trimmer attachment fit onto my trimmer. I want to use as thick a line as possible and the T55x head attachment is the only one that seems to hold greater than 0.130" trimmer line as well as being tap advance. I know you can use a brush blade but i don't need that cause I have a lot of HEAVY overgrowth around concrete bases, buildings with metal siding etc. that a blade would tear through...any suggestions?