The response I received from the mothership..."We have not tested the interchangeability of the ECU's and therefore do not recommend it. This may cause issues with driveability, performance, and/or on-board diagnostics. Again, this not not recommended."
Sure sounds like, "Well, we haven't tried it, but the lawyers do not want us doing anything that would take us afoul of Dear Leader and his minions at the EPA."
I am going to do a little more checking to verify pin outs, and then it looks like I will be ordering an ECU to "test".
palerider, Thanks for your vote of confidence and your valuable input into the conversation.