Torsion Bars

If your slant had factory AC, then the existing torsion bars are probably the same diameter as the 2-barrel 318 factory bars that year. You can find charts here in a search. I recall 0.85"D for V-8 and slant/AC most years, but don't rely on that. Not sure what "flimsy" means. Does it mean you can't adjust the height higher on the driver's side? There is a bolt you crank. Is it fully extended?

However, most people prefer thicker bars today, even >1"D, which may be too rough a ride for many. Those are after-market ~$250/pr. I got 0.87"D bars for my V-8 at a swap meet for $10/pr and he had several pairs on the table to choose. Usually sell for ~$70/pr on ebay. With used ones, you risk that they are sagged. At least you don't have a C body like me. Try finding affordable T-bars for those.