Tappet/lifter noise 207 1.4 16v

[Goforit]

Good morning campers

Just replaced the head gasket, had the head skimmed, and ground the valves... all working great but there's quite a tappet noise coming from the head. Eases slightly with higher revs but having researched it I think should have put new hydraulic lifters in. I'm not going to strip it all down and do that but in researching I see there are a few additive products out the to help reduce tappet/lifter noise....
Has anyone on here used these products and would it help with this engine?

Many thanks
David.

[CitroJim]

Are you confident there's sufficient oil getting to the cambox to correctly pressurise the lifters? I'm wondering if in swapping head gaskets an oilway may have become either partially or fully blocked...

Can you tell if it's just one lifter, a few of them or all of them?