I have a 1994 automatic trans am and a 1993 manual z28. I am going to swap the automatic in the z28 and put the manual in the trans am. I have done some research on the wiring but I was wondering if it would just be easier to just swap the harness inside the vehicle. Is this easier since I have two complete cars?

 

The 94 has an electronically controlled 4L60E. The 93 ECM cannot control the 4L60E. The 93's used the non-electronic 4L60. Won't work unless you use an aftermarket stand-alone transmission controller.

 

I was going to swap the ecms and the wiring harness for the engines. I think that would still work, right?

 

It is definitely not "plug and play".

You have to swap the MAF sensor into the 93. The 93 tach is driven off the coil through a filter. 94 tach is driven off the PCM. As I understand it, you may need an aftermarket ignition box in the 94 to drive the 94 tach off the 93 engine. I think there may also be a mismatch on the speedo pulses per mile. If the rear axle ratios are different in the two cars, you will need the 94 PCM flashed to the correct rear axle ratio, and an adapter for the 93 VSS.

Then you will find mismatches between the engine harness connectors and the body harness connectors. You will have to sort through the wiring for each body connector, and repin the connectors to match the engine harness. Shoebox has a list of the body harness connector pinouts for each connector. Note that there are tabs at the bottom of the page for each connector.

http://shbox.com/1/harness_connector_faces.htm

The 93 is called an "ECM" because it only controls the engine. 94 and up is called a "PCM" because it controls the powertrain (engine + transmission).

 

Thanks for all the information.