How do I figure out which of 4 types of transmissions fit my 2000 Impala?

there is something called a RPO code which stands for Regular Production Option the list on the car is usually located either on the spare tire lid in the trunk or in the glove box or on the center console lid or under the hood the list is of all rpo codes equipped in your vehicle look for which l code you have lbb, lpb, lcb, or lnb tell me which one u have and i can try to decifer it for you or u can at least what power option you have

I have a 2002 Chevy Impala and all the lights will come on but the car want start and the radio said a 702 code what is that