Yes they did. All the 2002 ZL1 Supercar engines got special stamping as well as other parts of the cars. The engines have the Phase number (1,2,or3) on it, the date installed, the car number and the last 8 of the VIN of the car, and some other internal codes. The Phase 3 motors were also specially stamped.
For more cool photos and info check this web page out.
http://www.gmmginc.net/ZL1/gallery/index.htm
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