340 cam
Dang green1. This sucker is really fighting you.
Lifters will bleed down over time. Sometimes mine do and sometimes they don't. My guess is that depends on if the oil hole on the lifter and the lifter bore line up when the engine is stopped. That's just a stab in the dark though and I don't know for sure.
Check all the cam lobes before you bolt the manifold back on and make sure your cam hasn't gone south. Also, if one head was milled and one wasn't, it could be the cause of your water leak and give you a big vacuum leak too.