Gordon,
Two more quick thoughts:
Raising you pressure should get you better gas mileage and, if your tires are more than 8-10 years old, you're ready for new ones.
When I got my '69 OTS 16 years ago, they came with tires about 9 years old. It wasn't long before I felt my rear end (aka butt) shifting to the left when I made a right hand turn from a stop. Turns out the left rear sidewall had split and the tire was rolling to the side.
Best wishes,