What is the purpose? If simply to get it running, it will only plug in with a california spec d15z1, due to the cali spec NOT having 5wire wideband and lean burn mode. federal 49state will use those, and be unable to work. Plus EGR throws a wrench into things, it might change the pinout enough to be troublesome.
If it is a fuel economy project, and you are interested in getting the d15z1 to work, swap to a d16z6 harness, and make sure you tune the vtec engagement point down to the Z1's spec, which is probably right around 1500-2500 rpms, and you limit redline to 5900 rpms or whatever the Z1's are rated for. Fuel and ignition maps will need a lot of work as well. You can run a lot more timing with the d15z1 though, so you can certainly maintain a lot of its torque.
a d16z6 ecu will run the vtec way too high in the rpm range, it will set the redline far above the d15z1's ability, and run puking rich everywhere.
The d15z1 needs its own ecu to run properly, or it needs to be fully tuned. It is a leaner burning engine with a very high lean tolerance towards fuel economy.
head gasket, you can find that info very easily. Check local autoparts store websites. Write down the part numebrs while searching for both a DX and a VX civic. You will find some similarities in parts.
