Stock GM Hei ?

[Daves72'GMC]

I have a '72 GMC with the 402BB and I want to change my stock distributor to a stock GM Hei and a friend of mine gave me an Hei. People on the board said for me to get a '73 Hei. I took my Hei down to Napa and their Hei was a little different than mine. My hei has plates right under the Cap and no rotor and has a codensor and a black electrical piece with 2- screws and says GM on it. Napa's Hei doesn't have the plates right under the cap and looks to have a rotor on it. The Napa guy gave me a price for the rotor , so his uses a rotor. Is mine a later Hei or a computer controlled hei? Which one do I need? I don't want to use mine because it's very dirty and I don't want to go through the hassle of rebuilding it. Thanks everyone.