These motors can sound diesel like when cold. Mostly I think the noisiness comes from piston slap which diminishes as the pistons expand. If it all quiets down when warmed up - not to worry - it'll run for near forever like that. As far as the hushers go--They slip onto the top of the valve stem above the retainers. Before you remove the cam check the valve clearance (once the new hushers are in place you won't be able to get an accurate feeler gage reading) and record the figures. After the cam is out lift out the bucket tappets and measure the shims if the clearance needed adjusting. The old hushers that remain in place with be brittle--often they've already disintegrated and the bits will be lying at the bottom--or they stay stuck to the inside of the bucket--be sure to look before replacing the buckets.