vpc chip question

[1stGenRocks]

ok this is a dumb question but i've searched and asked people and can't find what i need.

People talk about having a 550 vpc chip or a 450 vpc chip. Is this a chip in the vpc box or is it the eprom in the ecu? The reason im asking is because i bought my car with the vpc but they kept the eprom ecu so im using mine from my other car. I'm planning to buy a stage3 dsmchip soon but i need to know what the deal is about the "vpc chip"

 

[1stGenRocks]

Just for the search. Since it was warm out I was out tweaking the car and opened up the vpc box just to check. the vpc chip is in the control box and has a stickie label on top that says 450.

 

[laserspeeddemon]

There is a chip in the VPC AND there maybe a chip in the ECU, known as an EPROM chip.