Hmmmm. The wheels in my head are spinning again

Ok it’s been awhile so I give a small update. Let’s start out by saying I wouldn’t recommend using the 9/16 tubing unless you have LOTS of patients, tools, and a hole in your head. Would I do it again? Probably because and only because I have one more machined block sitting here. When I start out with a fresh unmachined block it’s getting drilled out to 5/8 and getting the 1/2 inch inside diameter soft copper pipe I have sitting here for this job. The stainless is slightly oversized and very hard to work with. Four lifter bores are fitted with four more to go.