I always get confused about the initial mating of the block to head. No one mentions position of pistons TDC1? and the intial positions of cams so the valves don't come into contact with pistons🤔
I usually put the head on and cams in with no pistons at TDC, but with piston 1 close to TDC. Now if the cams are already installed on the head, I'll get the double dots lined up and some valves are sticking out, then it's a matter of just keeping piston 1 like a slight bit counter clockwise of TDC until the head is torqued down, then move it back to TDC after.
I never disassembled mine, but it's not a bad idea to clean them out and re-prime them. But yeah they'll be fully collapsed on initial startup if they're dry.