I don't know about the gain of 10 HP but it does wonders on the ATX. It changes shift points and it gets rid of the limiter (Superchip) I bought mine new from Kurtz Kustomz
www.kustomz.com for about $230. Look in the classifieds they usually go for about $100 to $150. Kurtz Kustomz also reprograms chips. Just make sure before you get one that they have the program for your computer code.

They don't have all the codes.