If you are building the motor, do the head work. Like they say you make power with the heads and you hold the power with the block. Cams, port/ bowl and valve train work will make the turbo work more efficiently and extend your power band to the right and if done right will extend the PB to the left. I did the head work on my build and have a solid 4k power band! I have a Dom 3.5XTR because I had a bit invested in a custom up pipe & EWG exhaust work with my Killer B header. If I was to rotate a turbo on my build this 6266CEA is the turbo I would use!