What cam should I get?

It is 4bbl now and I don't know what it had factory. The guy I bought the car from wouldn't know what cam size is in it either. I have the paper work of the engine rebuild but it just says cam and gives the price but not the size. I was looking at Summit and Mopar performance has bigger cams than that for the 273 only. So I figure they must have tested these cams to be alright for the 273. When I had the Charger I told my buds about what cam I was going to run and some said thats to big and others said that would be fine. So I installed it myself and man did that car get up a go! It had a good take off and pulled alway through the run. But I'm opened ears for all comments.