I have an upper A Arm with a small crack in it but, it does not go all the way thru. Its about 1 inch long. Repair with weld or replace? The crack is in the middle of it not near any bolt holes or ball joint mounting areas. I am thinking just weld and grind it down. Any advice is welcomed.

Replace!!

What Wild Bill said X2 !!!!!!!

Replace it, you can't afford to have a failure. You might want to check the other side also. If want to keep it original then check this site out.
Good luck Ray

http://www.leverfamilysite.com/controlarms.htm

I'd replace it ..
also while its apart ...... INSPECT the lowers as they are the ones that normally crack !!!