I think about setting up a part 15 am station if were to get a SSTran & 102" whip how much range should I expect to get? With this setup could I get 4 miles & could I link 4 or 6 of them together.
Sorry, but you will not achieve a mile range with what you describe. The SSTRAN is a great unit with very good audio but, as is true for all part 15 AM legally operated transmitters, the range is limited such that the distances you mentioned are rarely achieved.
You can expect a range using a good car radio as a receiver and the setup you describe of about 500 feet usable signal. Keep in mind that the car radio has great advantages over the typical home based receiver. They are sensitive and usually away from noise sources such as light dimmers, motors, fluorescent lamps, etc. but due to the limited range of part 15 stations the audience will not be mobile.
The SSTRAN can perform much better rangewise if you build a base loaded antenna and ground radial system as detailed on the SSTRAN website (click on their link on the left panel here). Except in rare situations, a 2 to 4 mile range from any part 15 station operated legally is not to be expected.
Neil