If it’s never seen maintenance, remove and lubricate all the pivot points including removing the sway bar bushings and clean them well. The highlifter springs are very stiff. I put them on when plowing as I add about 120 lbs on the rack for traction. The stock springs may be to soft for farm work. In any case , the lift will wear out your cv joints much faster. Once the springs are off he shock, you may determine the shocks are in fact ok.