[nismoron]

In the US they had
89-90 S13 240sx with KA24E (single overhead cam)
91-94 S13 240sx with KA34DE (dual overhead cams)
95-96 S14 240sx with KA24DE (more rounded headlights)
97-97 S14 240sx with KA24DE Zenki (angled pissed off looking headlights)

The following motors were available overseas (never in US) but can be swapped in:
CA18DE and DET in 89-90 S13 180sx and silvia
SR20DE and DET in 91+ 180sx and silvia
The SR20DET came in a couple of versions:
(1)redtop came in S13= better flowing head. the one to get if you are going all out for 350+hp.
(2)Blacktop came in S14= little better turbo but less head flow. the one to get if you are going to leave it fairly stock.
(3)Blacktop from S15= better turbo than the 14 but has the unreliable 6 speed and a wiring architechure different from the US cars=harder to wire in.
And the KING DADDY OF 240 swaps:
(4)RB20DET from R32 Skyline ( I have this one) just bolts right in like an SR but easier.
(5)RB25DET from R33 GT25T Skyline bolts right in S14. tight in an S13 due to larger tranny.

The 240sx's came in:
base model= roll up windows/manual door locks, no sunroof, hubcaps, no spoiler.

SE=power windows and locks, cruise, spoiler and option for sunroof, alloy wheels, optional HUD guages
LE= same as SE but had leather interior and HUD guages and standard sunroof.

Engine breakdown is as follows
KA/24/DE SR/20/DET
first letters are engine family
numbers equal displacement in liters 24=2.4 liters/20 =2.0 liters
D= dual overhead cams (no D means single cam)
E= electronic fuel injection
T= Turbo (TT =twin turbo like RB26DETT or VG30DETT)