instead of cutting off the servo ear, try trimming some material off the ta05 chassis. you're using the stock TA05 moulded plastic chassis, right? i did this to my chassis and the servo fit with all 4 ears intact.

its easy to do with a dremel and a file. see where the servo ear will hit the center of the chassis and remove a bit of material there.

but if youre going to race in TCS or a similar series, check with the rules first. i think you are not allowed to do any chassis mods.