People, there is a better way
If you have a Harbor Freight store near you and you also have an air compressor, you may want to look into getting a pneumatic air hammer with a pickle fork attachment. It is much easier than banging anything by swinging a hammer and a lot less stressful to the parts involved. I suggest HF because they are cheap, and a good source for tools you will only use once or very rarely. You may find a better tool at a price you can live with somewhere else. Once you use the air hammer method of separating ball joints and tie-rods, you won't want to use anything else.
Yes, the pickle fork tends to rip the boot, but most ball joints I have dealt with have a replaceable service boot available or can be fixed with a universal service replacement boot. And by using a sledge hammer on the outside of the A-arm or tie-rod, you are putting unnecessary stress on the rest of the front end and taking a chance on cracking the part you are hitting, not to mention the possibility of wild swings that could really do some damage. And past that, my experience has shown that ball joints and tie-rod ends are cheaper to replace than having a loose front end prematurely wear out tires.
1990 LE -wrong bumper