[ledzeppelin240]

There are quite a few reasons for using a LS1.

-1hp & 1lb.-ft. of torque per cubic inch displacement.
-128lbs. lighter than the KA
-with a T56 you now have 6 gears.
-the LS1 is one of the best small block v8's (this is my opinion based on what I have read, seen, and heard about), you got the refinement, technology that is reliable, durability, fuel efficent, good emissions, capable of making high hp with minimal modifications, or running low 12's in the 1/4 mile completly stock.

I believe it has a lot to do with preference and what you want to work on or what you want from the car. There are so many options for the 240SX which is why I love this car. Everything from NA KA power, KA-T, SR, RB, Nissan V6's, Nissan V8's, Toyota V8's, LS1's, Ford 302's. I have decided to use the LS1 because of its performance and basically bang for the buck after looking into half of those options.