ride height
Too low a ride height, too small torsion bars, worn out shocks, bad alignment etc. could all contribute to what you describe. Download a factory service manual, the ride height process and alignment specs are there. Here's what you're looking for, might be a bit small to read easily. "V&L" line are what you want to follow. And since you actually have bias ply's, these are the numbers you want to use. If you change to radials, use the SKOSH chart for alignment specs.
Too low a ride height, too small torsion bars, worn out shocks, bad alignment etc. could all contribute to what you describe. Download a factory service manual, the ride height process and alignment specs are there. Here's what you're looking for, might be a bit small to read easily. "V&L" line are what you want to follow. And since you actually have bias ply's, these are the numbers you want to use. If you change to radials, use the SKOSH chart for alignment specs.