Nose high......
Unstable towing
Lighter pin weight which can cause 'chucking'
More weight transferred to rear axle/tires/suspension
As suggested......
Axle flip (moving springs from under axles to on top of axles-----really more of a 'spring flip' :B )

IF springs are already on top of axles.....
Then frame lift via square tubing
Cut spring shackles off of frame
Weld on square tubing (3", 4" etc)
Weld shackles back on
Then weld cross tubing from one side to other side at shackles fro reinforcement
