39 wheel dimension

Yes I would seriously forget about numbers and measurements until you have the actual tires/wheels you are going to use, and they are mocked up under the fenders of the actual car you want to put them in at the ride height you want and in the position where you want them. When you've done all that and it's sitting there in front of you and looks right and you haven't had to rely on anyone else's experience or opinion (not that it's probably not inaccurate), then and only then get a tape measure out, do between the wheel mounting surfaces which is all you really care about and hand that to the guy doing the rear. I've driven myself nuts adding and subtracting numbers gotten from whatever collection of sources to arrive at what is in part a subjective thing anyway and have the car not look right when it was all finished and have to do it all over again.