I relaced the sway bar end links on my '70 and I'm not sure how much to tighten the nuts? Any help would be greatly appreciated.

Tighten them down until the rubber bushing swells out to the diameter of the washer. Not too scientific, but it works. If you leave them too loose, they will dis-assemble as you drive.

The torque of the end links contributes to the bars effectivness. Leaving them loose will run the sta-bar soft, over-torquing will run the bar tight. Changing from rubber to poly also changes the bars effectiveness. Most good link kits either include double nuts or locking nuts to prevent them form backing off. Torque until bushing starts to "squish" out.

Thanks!