I am interested in getting a tune and injectors. I currnetly am running a 3 in pulley with a cai and am boosting 15 lbs. My question is if I send in my PCM rather than pay the core charge will I still need to have a case learn performed? Also how long is the turn around on you part between arival tune and shipping it back? I was thinking the stage 3 tune would be good since it claims 15lbs. of boost and that's what i'm making. Lastly are there any instructions for installing the injectors?