Not too thread jack, but I'm in the same position as OP. My turbo is dead (spitting oil) and I'm looking to convert to t4. Built 7m, 272s, forged everything, fuel system, etc. I'm limited to 91 california pump. Will the 6266 be able to make close to 500rwhp at 18psi on a maft-pro or should I be looking into the 6766?