[blykins]

I've been using them for several years. I'll have to look back at my notes and see when I built the first one.

Turns out, the first one that I used, I had it pressure tested (standard fare for all aftermarket blocks I use, stems from my experience with Dove products) and it bubbled up through a couple of lifter bores. They back up against the water around the cylinders and if there's any porosity, they will bubble out there.