Technical Data:
1.6L (1590 cc) DOHC 16v
130-135 hp @ 6800 rpm
Redline 7200rpm*
Bore 75.0
Stroke 90.0
Compression Ratio  9.5:1

4th Generation Civic (1988-1991) DOHC ZC Identification:
There are several ZC's that were made:
D16A8 (European). featuring EFI w/catalytic converter
D16A9 (European). featuring Carbs w/o catalytic converter
ZC (JDM). featuring EFI
The DOHC ZC comes with a black valve cover with the cover bolts on the sides
The Honda symbol is on the exhaust side of the valve cover
The DOHC ZC comes with a 4-2-1 header style exhaust manifold
The DOHC ZC comes with a small oil to water oil cooler on the back of the block
The DOHC ZC has the same mounting points as the standard USDM 88-91 CRX/CIVIC

Swap Info:
The DOHC ZC will bolt right in to the 88-91 CRX/CIVIC no fabricating or welding is needed
The swap can use your existing wiring harness if you have an SI, if you have a DX then minor modification is necessary. There is info on this procedure at the Honda Hybrid Page

You can use the SI ecu, but plan on upgrading to a 88-89 Integra ecu. The Integra ecu features more aggressive fuel and ignition maps and also allows a higher rev-limit (7500 rpm). The Integra ecu will hook up directly to the SI wiring harness and takes about five minutes to do. WARNING! only the 5-speed ecu will work, when you go to get the ecu ask the place that you are getting it at if you can test it first. Install it in the parking lot, let the car idle for five minutes then drive around and make sure it drives right. Test before you buy.

You can use the SI or DX transmissions, they both bolt up. You can also use the SI or DX flywheel.
The engine only adds about twenty-five pounds to the front of the car, so your steering and suspension should be the same. If you are still concerned about the added weight, move your battery to your trunk.

Maintenance:
Spark plugs: NGK BCPR6E-11
Timing belt: Part no. 14400-PK2-004 (same as 88 Prelude)
Oil filter: Same as 88-89 Integra. Fram part no. PH3539A
Oil pan gasket: Same as 88-91 CRX/CIVIC or 86-89 Integra
Spark plug wires: Same as 86-89 Integra
Distributor cap and rotor: you can use the 88-91 CRX/CIVIC SI or 88-89 Integra

Modifications:
Throttle body is the same as the 88-91 CRX/CIVIC SI
Upgrade your exhaust. This makes a big difference in power
88-89 Integra ecu will make an even bigger difference in power
The internals of the ZC feature dome shaped pistons and rods that are a little stronger then the CRX/CIVIC SI

HKS makes cams for the ZC, here are the specs, 256 degrees intake and exhaust duration, 5.95mm Intake lift, 5.3 mm exhaust lift, they are ground from new billets.
I have seen a turbocharged ZC before, he was running mid 13's sorry I have no technical data
There is a rumor that Greddy/Trust originally designed the 92-95 Civic turbo kit for the ZC CRX. With a little fabrication this kit should work on a ZC.

Header: any D16 series header will match the bolt holes, but the ports wont match correctly. Using a header made for a 88-91 CRX/CIVIC SI and grinding the ports(on the header) works great.
Please read this post that gives a good explanation:

"The scoop on the headers, is that while the bolt pattern for the Civic SOHC engines and the ZC engines are identical, the port pattern is not. The ZC engine has the ports shifted almost 3 mm (appx 1/8"). In real terms, this means that when you use the SOHC header, the ports do not align properly. The exiting exhaust gases literally run into one edge of the misaligned header flange. You can see this by holding the steel exhaust gasket from the ZC engine up to the DC header.

The easiest and best solution is to use the ZC gasket as a template and mark the misalignment. Using an air grinder, with a small stone "port" the header to match the ZC port configuration. While you're at it clean up the entry point of the header a little so that the whole port on the header is slightly larger than the ZC port. It is an old, but proven trick that the larger header port decreases the chance of exhaust gas reversing flow and re-entering the still open exhaust valves. It is better to have the port larger than to have them matched identical. Do not under any circumstances grind the port on the head to match the header though. This gives poor results."

Source: http://dohc_zc.tripod.com/
Swap: http://thenew.gamesbbs.com/~dmoore/zc.htm