More rambling from on old geezer: Seems bizarre that you can collapse the lifters just pushing down on pushrods.I've seen oil pickups get a little air sucked into pump. Usually if bad enough the pump won't prime immediately when starting. But still shows good pressure as you noted. Had a couple guys install new pump and later discover the pump cover screws were loose and getting looser. Just cause something's new doesn't mean a thing. I'll presume you're reading OP along lifter galley. Make a small clear plastic line connected to that point . Let it drain into rocker cover area. See if air bubbles continue. Wondered if your cam & lifter combo places the lifter oil groove in the block's galley fully enough for sufficient feed volume, Those pushrods usually squirt quite a bit requiring the little clip on "umbrella" tools saving a big mess while adjusting running. Don't know your usage of the engine, but 115 seat seems high. What's open pressure? Verified during installation? David
