Dear bigben3:

The best additive to unstick and quiet noisy lifters is Marvel Mystery Oil (now owned by TurtleWax). Search the forums for long threads about this additive.

BTW, try to switch to a different oil brand or use Valvoline Maxlife Engine Oil. Maxlife Oil has very good cleaning additives and seal-stop leak additive as well. I tried it on some old cars and it was like a miracle.

Eric