There is nothing that directly works.
On the passenger side, best bet is to get a 84/85 Turbo Regal valve coer. It will have no holes and the bevel back edge. 86/87 will have a breather hole in the front.
On the drivers side, a no hole cover from a 1985-ish FWD with a Buick 3.8 will work, but will somehow need an oil fill/breather hole installed.