(Auto Tranny,1978 FSB, completely stock with just over 100K original miles) When I put in reverse, drive shaft dips, then put in drive and drive shaft corrects. Clunking noise when I put in gear, and odd 'Chirpping' noise as I accelerate, but diminishes when I back off accelerator. What could be the problem? Also I am putting in a 4" suspension lift; new WH Coil, new 9 leaf in rear, shocks, etc. Will I need to get new drive shafts anyway?