MONGOOSE LEGION L 500 ( only the frame brake caliper and the crank arms remained from the original bike )

So I bought a MONGOOSE legion L500 Pretty cheap last summer and have been changing a lot of parts. But this is it so far and I am just about the change the crank to a blank 160 mm the 175 I keep catching my heal on the back peg .what's your thoughts. I I ow people are going to say why a mongoose legion l500 .why not get a real good frame.