I have a '95 del Sol S (1.5L non-VTEC). A year ago, I picked up a '95 Civic EX engine (1.6L VTEC - D16Z6 with a P28 ECU). The guy cut some of the wires on the harness when he pulled the engine.
I have not looked, since the car is at a friend's house (he is doing the swap for me). I think that the 1.5L harness has 2 sets of wires and 2 connectors to the ECU, whereas the 1.6L has 3 sets of wires and connectors. From what I understand, I can use the existing wires and connectors from the 1.5L on the 1.6L engine and ECU. I will need to install the 3rd set of wires and connector in order to make the VTEC system operate.