I just got new aluminum valve covers for my z28 and the holes are different sizes. What do you guys do to get the oil fill and the pcv hose fitting to fit. Thanks

 

Go to the local auto parts store and get new caps and grommets.

 

will they have a fitting so i can use my pcv pipe?

 

You get a "grommet".... a rubber ring that pushes into the hole in the valve cover to make a seal. Then you push the elbow for the PVC fresh air supply hose into the grommet. You may be able to use the grommet out of your old stock cover.

Measure the inside diameter of the hole in your new valve cover. Measure the outside diameter of the plastic elbow for the PCV tube, and get a grommet that fills the gap.