different motors have been swapped into 240s. SR20DET and RB26 or RB25 motors are also a popular swap.
Depending on how much you want to spend almost anything is possible. LS1's from corvettes, or 2jz-gte from the Supra are all possible but require a ton of money to make it work properly.
Yes it will fit in but it will not bolt up to transmission
Absolutely.
A SOCH 240SX transmission will fit a DOCH engine. They have the same gearing and bolt pattern so they are compatible.
yep
Yea, a 300ZX's engine can fit into a 240SX although there might be some need for adjustments in the engine bay.
Nope, different body styles
if they are both turbod then yes, no if they aren't the manifolds are different
Yes, some '92 240sx' came with the ka24de motor.
yes with heavy modification
yes it will with the correct engine mounts, cross member and loom
no it will not. To fit 97-98 headlights onto a 95-96 240sx you will need these 97-98 240sx parts: headlights hood front fenders front bumper front grill maybe the front bumper support
no the civic engine is a transaxle not rw