What ECM is installed in the vehicle? If it's the old '7730 ECM, the CALPAK can be changed. If it's the newer flash-ROM ECM, you can't do it with a "chip" and even if you could, HyperScrap would be my last choice, right after a stock upgrade (of which there are many). I've burned quite a few PROMs for the older ECMs, and decompiled some of HyperTech's code, and there is not a lot of thought involved in their "upgrade" products.
Visit
www.moates.net for a lot more information on the subject.