bowing basement walls

My home was built in 1958 and the basement walls are bowing. I had a water system installed to take care of the water coming in the crack between the wall and the floor. I have asked a lot of questions and one person told me that the heavy stone on the exterior, is what is causing it to bow since at that time they did not add rods to the inside of the block wall for strength. Those peices of stone are heavy as teher are a few left over. The house has sunk about I/2 inch on front and back.
any ideas about the best way to fix it?

[TJ1962]

The important part of your description is that the house has sunk 1/2 inch.

When a house sinks the walls break and then the lateral load takes over. Therefore if you provide a fix for a bowing wall a failure could occur. Settlement/sinking and lateral load/bowing is a different scenario. I have seen entire foundations replaced and five years later bowing started again. Why? Because continued settlement allowed it to break again.

Heavy stone on exterior would not contribute to sinking, necessarily. A soils engineer could do soil borings to confirm settlement. Piers would then be required to correct settlement, then you could deal with bowing walls. Options for bowing walls include: tie backs, steel beams and carbon fiber reinforcement.

Search membership list for your area to find a contractor that handles structural repairs and foundation piering.