There are a couple ways to tell that it's an E-body radio. I just read an article last week on this.
First of all, ALL E-body radios have the antenna port facing down. If it's out the back, it's not an E-body radio. Also, look at the two tabs on the front of the unit. The left side tab will be rectangular and the right one will be square.
Also, 1970 was the only year for the chrome preset buttons.