Sorry it took so long for me to respond. I usually only get on stangnet when I'm on my lunch break. The chip cost me $300 from JMS (Johnson Motor Sports) but I don't have the # handy. The chip is a must if you have 4:10's with an AODE because the gear throws the RPS's off so much. I'm not sure but I herd that up to 3:73's is fine without needing a chip. In addition to the shifting issues there are other benefits to the chip such as adjustments to the fuel and air curves, removing the boost retard, firming up the shift (I had mine set for very hard) and I also had them fix my CEL that was comming on arter I removed my EGR. Best of all I have 3 programs on mine that allows me to have advanced timing for normal driving and a retarded setting for when I add NOS in the future.