did you look at the body mounts? I know mine are pretty shot and prone to squeek. Also, the spring eye bushings are a known source of squeeking/popping sounds. In either case the part needs to be replaced
I had a similar noise....ended up being the front double cardan joint (or constant velocity joint) in the front driveline. It was dry from lack of service...and I was guilty of not finding it before it wore! It needs greased with a grease gun with a needle like fitting...guess about the size of a 20p nail. The u-joints were tight...but the double cardan joint worn.