I will have the valve retainers inspected by a shop that I trust when I'm getting the banjo bolts changed. If there is any sign of wear, I won't hesitate to put the AP2 retainers in. Since I already have the parts, it won't be much of a labor charge difference to change them out at that time. I'd go to Billman if I lived closer, yet I have access to Science of Speed. I had wanted to watch and assist, and now that may not be possible.