big let down car will not move now

Put the other wheels back on if you still have them. Test the car for drivability. If all is well with the drive train and the brakes function properly, it is time to put the other wheels back on. Start with just the front and see what happens. If all is well, time to take a close look at the rears. If everything is new in back then I think you should check to see that the lugs are not bottoming out. I say this because if the new wheels are of a heavier gauge and they are tightened up, the lugs may not bottom out. This means the lugs will hold the wheel tighter to the drum, forcing it into a conflict with the frame of the shoe or the backing plate or both. If the old wheels turn fine, put three washers on the studs, replace the wheel and tighten. The washers will take up the clearance if there is any and you may find the wheel will not turn. If this is so and you have been driving the car it probably means that the lugs may have been tight, but the wheels not so much. This happened to me with after market Chinese drums, but it was the drums that were wrong. They can't quite convert the inches to metric it seems.