My suspension pops at times with the steering turned all the way in either direction. My mechanic says the ball joints are good.

I have a 1997 4x4 Blazer that does the same thing. It also does it some when I hit the brakes hard. I believe it is blown gas shocks. I have the OEM shocks with 93,000 miles. I have been meaning to change them just haven't got to it. If I push hard on the front end in a downward motion I notice it rebounds then there are a little bounce. On a good shock you should be able to push down hard & only get a rebound. Check yours & see what happens.
Once I do I'll post the results.

I installed new shocks last week.

I installed new shocks last week.

check your torsion bar mounts

My 99 Chevy S10 Blazer is 2wd. I believe that only the 4wd units have a torsion bar.

Could be a few things. Check you idler arm, and your pitman arm, make sure both are tight and not worn Make sure your a-arm/control arm bushings are good too.