SR20DET Oem Wire Harness Questions (or RX7)

[axelfoxx]

**90 240sx hatch**
so the shell i have now originally had a full sr20det which i traded for a lm7 v8.. and well sold.. now tomorrow i am either getting a perfect running fc rx7 na or ordering another sr20det from jdm tiger..
now.. if i go the new engine route.. instead of running a butchered ka wire harness will an oem lets say s13 redtop go perfectly into the chassis.. and the ecu if i get the same ecu with it too?.. or rewire and cut anythign just a hair.. because it seems like it would all go perfect i just want to double check and get a second opinion.. shell still has walbro 255 and some other left over goodies.. but i traded clutch hardline with sr20det so aftermarket is in order there too i suppose.. but yea any input on the wire harness or just getting the rx7 would be helpful

and no not a rotary flame war as they are actually pretty bad ass