I think I inadvertently tested my suspension and found I need softer rear springs!
I always intended my '46 roadster pickup to be used as a truck, and with that intent used stiff springs when I first built it. I found a pair of MGB front coils at a swap meet that were the perfect length and diameter, and using the extremely scientific method of figuring if they could support the front of an MGB they'd be fine on the back of a truck with less weight than the MG, I installed them. Sure the ride has always been a little "hard" it's a truck, right?
So... today I loaded the bed with 600lbs of concrete mix and drove home from Home Depot, when it suddenly dawned on me that the ride was smoother, with less rattles than usual too. I also realised I could feel the rear suspension working for probably the first time. So now I guess I need to fit softer springs, but not too soft or I won't be able to load the bed as I did today. Better get a little more scientific this time around methinks...