Plymouth Duster 1973 small block wheels

I think the OP is from the Dominican Republic. There may be a slight language barrier but here goes:

The 10 inch wide wheels are a real tight fit in the rear. They may fit with 4 1/2 inches of backspacing as long as the car sits at stock height or higher.
The 8 inch wide front wheels are going to be more difficult. If the backspacing is too little, the rim may contact the tie rod. Too much and the tire hits the fender while turning.
I'd advise to mount a wheel and measure where you have LOTS of room, then "add"size to the wheel. In other words, if the rim is say 6 inch wide and has 1 1/2" from the tie rod to the wheel, you can probably add 3/4" to that wheel and still have 3/4" clearance. If that same wheel has a tire on it about the same diameter as what you plan to use with the 15" wheel, try turning it full left and full right. Make note the clearance the tire has at the front of the wheel opening and at the rear. Again, if there is plenty of clearance, you can then add size there as well.