After doing some research and calling a few tuners (AA, VF, etc), I've found a kit that allows me to get 380 - 400rwhp @ 13 psi, while keeping the stock internals. According to a few tuners, the 2.8 engine is the best engine in the E36/39/46/90/92 to tune compared to the other engine models. The kit is from AA Tuning and will take approximately 2-3 weeks for build time. However, kit is going to cost $11K, EXCLUDING installs. Install will probably be $95/hr for 8-9 hours. I've found another kit by VF Engineering which puts down 310rwhp for 6K, but I really want more power possible. What do you guys think?