My 84' Chevy 1/2 ton seems to have some bad problems when weight is added to it either in the bed or on the trailer. The trailer only has a 3500# axle and did not even budge when the tree I fell was on it, however the truck handled very badly and when the bumper is stepped on the trucks bed twists and sags down about 8". The shocks on the truck are new and it sags about 2" when the empty trailer is set on the ball. The thoughts I have had: 1 - replace the stock springs with a set of 3/4 to springs. 2 - add a set of air shocks and air up when needed. 3 - add a air bag setup with with one of the small pumps for on the fly leveling. Please give me some ideas or suggestions on how any of these or other options I may have would work best for the money. I do not plan on keeping this truck in service for more than a year, but I need to take care of this problem for this upcoming season.