Doing cams and front structure

[Running rough]

I know on the 870's anything under 530 hp did not have what they call concept gears on the injection camshaft, just a regular gear, that is why the 500 and down had more of a rattle at ideal even when at operating temp, where the higher hp engines with the spring ajustment concept gear is so much more quite, due to taking the 'lash or play out', most of these moters with the concept gears have a distinct 'whine' when at operating temp,