Do i have to extend my drive shafts if i put a 3 inch suspension lift on my 92 jeep xj?

i didnt have to. you may check out jeepforum.com that site has many build and the issues or mods they have done. im looking into swaping a zj front shaft for my rear shaft in my xj. they say it will gain you a little length plus add the cv style shaft giving it the slip yoke elimintor touch with out breaking the bank. but all jepps are different you may have (little) vibration but i would say dont worry about it.

but when you have time check out jeepforum.com great ideas tips and tech stuff for the issues you may run into and the people are always willing to help out!