W2 Rocker Question

Long story short, I bought a set of vintage "ready to run" W2 heads with all the best parts including Crane rockers. After a few 1/4 mile runs I noticed that it was using a lot of water. After taking everything apart I found a hole or crack between the water jacket and one intake port that had been brazed - it did not hold. I now really want to replace both head castings but reuse all of the valves/springs/retainers/rocker arms.

My problem is that the only new W2 castings available use a rocker set up that oils through the pushrods and it is over $1000. Can new W2 heads be drilled to oil through the shafts? Or is there a source for new W2 castings that oil through the shafts?

At this point I am thinking about cutting my losses and selling all the usable W2 gear so I can buy a set of IMM Indy heads.