Quick question about BFG Radial T/A's

Well, Slantsixdan you've got me kinda worried about the tire stuff now haha. I talked to the previous owner of the car(also my personal mechanic, and Mopar fanatic(he's owned 8 Dusters, 3 Chargers, and 4 Cuda's) and he told me the 205/70R14 will fit on the wheels that are on there now with no problems, or modifications as he had them on the stock Slant 6's he had. I've already bought 2 tires this afternoon for $167. How can I tell if the wheels are 5 1/2"??