would a hatch si need wirings if b18 (GSR) was to drop in... i heard all wirings will plug in...

 

If motor is OBD I and you get OBD I ecu it's easy. It gets a little harder if ecu/motor are not obd I.

 

you would still need to wire a knock sensor and secondaries.... unless you use a skunk2 im, chipped p28 ecu which doesn't look for a knock sensor.
an obd2 motor in a obd1 car is no problem. its the same amount of wiring.

 

so will the 94-97 GSR ecu fit rite in my stock civic si?

 

94-97 will fit in your si, but 97 is OBD-II, so you'd have to get a 2nd 02 sensor, a jumper or pigtail to plug in the ECU, and some other **** too.

 

so ur saying the obd1 GSR ecu will jux plug rite in while takin the stock si ecu out.?