Jose Alfredo Lopez

Hi guys, Im new here and just wanted to see if I can be point in the right direction. I am working out on an 01 (GTM800) Singe cab short box. Its a roller and will be getting the LQ9 treatment but cant tell if there is a difference between the 99-02 Round Headlights/front end and the 03+ square head lights/ front end? I mean is there a common abbreviation to tell them apart? I am trying to research what fits what and what I need to do the updated look. Im sure it has been done and I rather find a build thread or DIY then to ask something that his been done before and not clutter the forum. Also looking into the possibility of a 6 speed swap but not sure if any GMT800s came in manual transmission or not.