When you say ZA CD, do you mean the OBDII->I CD, or the 24v swap CD? The swap CD is good but they do a bit too much. The other problem with it is that they do an M50 swap, you're doing an S52. Overall the OBDI conversion is pretty trivial but none of the sensors are compatible. The S52 even has the trigger wheel at the front, and a bracket for the OBDI crank sensor, but you do need to buy one. The cam sensor is different too. The knock sensors won't work, same with the temp sensor for the engine. The S52 has a single sensor which sends the temp signal to the computer and cluster. So the head only has one sensor hole. You need to get a DME temp sensor for the one hole, and either drill/tap a hole for the cluster, or use the Zionsville temp manifold (good, clean solution).