I'm no expert but for what it's worth... Manton makes an adjuster that is hollow.http://www.mantonpushrods.com/ This will allow the oil to lube the cup. Whe had problem with the intakes and this solved the problem.
That spray bar looks like another obstacle while adjusting the rockers. And for some reason I can just see them coming falling out. Bouncing around in there would not be a pretty sight.