1" rear end lift questions

I had a shop fabricate some under the axle duals for my car and they recommended that i buy a spacer that i think goes under or on top of each rear coil that would raise the rear end up about 1". They said that this would help me gain some ground cleanrance and help the car handle better. Can someone tell me if this is true? They also thought this spacer is a GM part, does anyone know if this part exists?
Any input is appreciated.
Thanks

How would raising the body increase clearance for under the axle duals? Raising the body would pull the exhaust up closer to the axle tubes, but you could have done that by adjusting the hangers. It won't gain you any ground clearance, because the axle tubes are going to be the same height above the road, no matter how high you lift the body.

And there is no way that raising the back of the car would improve handling. Raising the car's center of gravity is going in the wrong direction.

They've been welding on too much galvanized metal in poor ventilation.

The spacers they spoke of are already installed. They are about 1" thick and between the body and the rear springs.

Should have gone over the axle. Under never works out good.

Re'

Fred's spot on as usual! Also lifting the rear, besides not solving your problem, is going to generate some ugly wheel well gap in the back.

yeah i decided ill just pay the big $$$ to have it run over the axle, thanks for the replys.