Since Ive got the head off (91 CRX HF)I was wondering about changing the piston rings, but I have no clue where to buy them. Looked online and found nothing to beat an advance auto price yet. Are there any companies I want to hunt for or stray away from? I was also wondering if there was a way to test the rings with the head off to see if I should even waste my time. And finally what oversize rings do for a car and if there would be any reason for me to put oversize in my delivery car.