Ideas on what's causing my click/tick/rattle noise?

halfafish said

I have no idea, and I didn't know there was such a thing as a valve rotator. How would I figure that out?

Click to expand...

Rotators were used on various engines' exhaust valve instead of a standard retainer, they were designed to "rotate" the exhaust valve during operation to prevent carbon buildup (after the introduction of unleaded fuel). They are a substantially thicker multi-piece design that by necessity used a slightly shorter valve spring. However, I have no idea if or when they were used on slants... just a possibility.