Diablo chip location?

[99 svt]

When I bought my svt I was told it was tuned with a Diablo chip. Where does this chip plug into the system, and is it removable? I am planning on getting an X-cal 2 programmed for my car and don't want the tune from the Diablo messing up the x-cal initial tune. Thanks.

 

[Barge]

A good place to start looking would be the ECU itself.