Lack of torque in my 5.2

Hello! I searched the forums and could only find similar questions regarding the 4.0, but my Jeep seems to lack some oomph. I have a 1993 ZJ with the 5.2 with 210,000 miles with a 3.5 inch lift on 31's. I was towing a car home the other day and it just hit me how much it was taking for my Jeep to pull it. My dad has a 98 ZJ (with 270,000 miles) and he tows stuff all the time and most the time you can barely tell you're towing something. My Jeep seems to run fine, no check engine light, not missing or anything, but it feels like I'm just lacking low end power. Is there anything I should look for maintenance wise, or any upgrades I could do to gain more torque?