Will this combo work?

after recently installing a au motor in my ef, i was shocked to find the tappets are loud as f**k..so i thought this would be a good opportunity to replace the tappets in the ef motor and simply replace the rocker assembly in one hit (can't have car off the road..)

I know i could just replace the au ones, but seeing as i have more cam options with the ef ill be doing that if its possible?

or does anyone know how to quieten down the tappets in the au motor? its only done 60 000km's before rebuild, but it was sitting on a stand for 1 year and its done 600km's now and not getting queiter (2 oil changes also.) is tappet stop noise additive worth a shot? will the cause damage to any other parts of the fresh motor?