I've got a F150 looking to run 38.5" tire's.  I was looking into a 6" lift but the thought of an 8" lift was more in store.  Just wondering if with a 8" lift if there is going to be any problems with having to replace the drive shaft's or anything like that?  This is strictly a mud truck no highway driving.  

I would highly recommend new drive shafts with that much lift. You may get by fine but it would just suck to have to get out in the mud and fish your driveshaft out.  

FourWheeler Web Editor:
I would highly recommend new drive shafts with that much lift. You may get by fine but it would just suck to have to get out in the mud and fish your driveshaft out.

He needs more than drive shafts. He needs new axles and some 5.13 gears for 38's and needs to loose the TTB front end too. People loose drive shafts primarily because they do not regear their 4x4's with lifts and big tires and do not give a remote thought to the torque load increase that this places on drive shafts with big tires and stock gears. Deeper gears not only restore power and effective gear ratios with big tires but they also greatly reduce average torque load on drive shafts too.