I'm not going to B.S. you, you won't make that on this size turbo, safely if at all...
My goals on my current setup were 200-250whp, and was happy to find this size would suit my needs. I read, and don't quote me on this someone making 265whp on a turbo of this size...
For current verification purposes:
http://www.mx6.com/forums/1g-mx6-for...rd-turbos.html
Post #7
"223whp at 8PSI on a Ka24e"
(What are the odds after my hour of searcing, using a million different combinations of search tags on google, I find something directly related to a 240sx, score.)
So, in the end, desperate or not, I won't B.S. yah: I highly doubt this turbo will fit your power goals, safely, if at all. The choice is yours on where you'd like to go from here, I should be on all night and will respond quickly.