Do you mean you put wheel spacers in that moved your front wheels out farther away from the truck? That will probably put more leverage on the suspension, making the truck sit lower. This would cause the tires to lean in towards the truck (top is closer than the bottom). An alignment will fix the camber problem, but this will be hard on the already weak design of the wheel bearings.
If you put coil spacers in and the tires are leaning out, the top away from the truck, an alignment will fix this also.