I had a th350 done by a friends . he used transtar reman kit and a noyoyo shift correction/improver kit . thing works super . 4.10 / 33" tires it would chirp tires 1-2 shift . but the shift kit wasn't so hard it would anoy the hell out of ya driving it .

All kidding aside, the paint will make it easier for mud and dirt to rinse off and wont retain a noticeable amount of heat over the raw finish.