Been done a lot guys. All that's needed is to locate where on the deck to drill the oil supply holes and drill to the cam bearing bore. Just one hole per side. Any competent machine shop can do it.
It's not easy and I've never heard of it being done. The hourly labor to set up and drill that particular hole is going to be 1/2 the cost of the EQs and then you can bolt on a worse flowing set of LA heads... It's small diameter, 6" long, on 3 axis, and the target is a 3/16" hole in located in the cam bearing.
Any of the shop owners here done this job?
If it was me and I lost the arguement I'd run the hollow pushrods and oil the rockers through there. It's worked for GM's rockers for years and they have 1/2 the surface area of a Mopar shaft system.
