TripleA1929

okay so i recently bought an 04 mustang convertable, its all black and i wanted to do a black and red color scheme so i figured id start with the interior lights. i bought leds online and put them in the cluster and when i turned it on i noticed it was very dim. i did some research and people said theres a green film on the back you can sand off but you have to take the whole thing apart. im not afraid of putting the needles back in and matching them up but i attampted this in my old car and whenever the rpm shot up the needle apmost lagged behind and they didnt match up. has anyone ever had any problems with their guages after doing an led upgrade?? should i just try getting brighter leds instead of sanding?? thanks