If you like installing nearly useless urethane those would be the ones. Assuming you have a basically stock shifter that has substantial side to side slop while in gear the real problem is the joint at the bottom of the stick. Put the car on jack stands to get under there and look. Have someone move the shifter in the car and observe where you have play in the linkage.
Parts 3, 4, 5, and 25 in this link are the likely problem. If the link doesn't work it's the standard parts break down for the 91 DX shift linkage. http://www.hondapartsdeals.com/hpa_part ... oupID=6039
I replaced these parts on both my HFs and reduced the play by 80 to 90 percent.