yeah i dont know where you guys are getting the idea that s14 sr to s14 is plug and play. I just went through the whole process and i wasnt really that bad, but you definatly have to do some mods to the wiring. i would say its on the same level as doing a s13 sr to s13. yes, on the s13 there are more plugs you have to worry about and there is no fsm available, but people have done it so many times and there arent too many variations in wiring harness between diff years. I had a Kouki s14 sr and found that is was very difficult to get any wiring info, i was kinda scared, but once you start going through it it will make sense.
Motor will drop right in.
Wiring, only mod is to the F4 plug by the ecu. I used this link
http://www.dragva.com/eng/F4.html
as a starting point and then did a lot of searching on different forums. Get the FSM for both the KA and SR and go from there. I think there was only like 1 wire different in the kouki plug. You will also have to do some splicing to get your wipers to work, but thats easy. I remember only having to splice about 8 main wires in order to get mine running, after that i cleaned stuff up a bit.