Need to replace faucet with new one and can't get the old moen off

Cannot ID your faucet. Can you check the model # for me one more time and re-post ? Is it kitchen or bathroom sink faucet ?

Have you checked to see how its attached beneath the sink ? There is usually a nut and washer attached to a bolt or perhaps the water lines that clamps the faucet to the sink.

You may need a basin wrench or fauucet wrench Are You Using the Right Wrench for Your Plumbing Project? | DoItYourself.com (http://www.doityourself.com/stry/typesofplumbwrench)
Its hard to get at the nuts once the sink is installed in the cabinet.

need to replace faucet with new one and can't get the old moen off
It doesn't make much difference what faucet you have. They all mount pretty much the same way. With retaining nuts under the counter or basin top. These can be a bear to loosen if you don't use a basin wrench, (see image) Most hardware stores have them in the tool department. Since the bolts and nuts are usually made of brass you won't find rust but squirting some WD40 on the threads might help. Good luck, Tom