I mean they make one that is a S247 that maxes at 350, but if you ever want more....well, now you have to swap out the turbo. Me personally, if I were in your shoes I would get more turbo than you think you will want as it only has to spool up in 1st gear. From there, boost is just a downshift away. I would go with the S256 with the .55 AR stainless housing. It would be capable of 550 max if you ever wanted to crank it up and with the stainless .55 AR housing, spool would be very quick. The stainless steel housing can drop spool time as much as 500 rpms due to the retained heat helping spool up the turbo faster.