Hi I might get it wrong but at the manual seems there's a 4th pully I don't have on my engine. What it is? At the drawing, it doesn't look like the power steering pump... And with the side draw (on the left corner) with the 3 pullies it says LG4 engine which is 305 but mine is 350. Anyway, I'm looking for new belts. I have 80 Z28 but the engine number is 3956618 which I understood it's from 69' area. Can anyone help with the right parts?