i need help from anyone who has built a mopar a body

They do, attached to new tubular adjustable A arms. Not really cheap however.

The F-Body spindle IS taller than the A-Body. Some people use it, although there will be some camber change through the motion of travel due to the change in geometry. If you are building a bracket car and occasional street cruiser, go for it. If you are building a street car with an eye towards handling, try to score the correct parts.