How are you adjusting them? The best most foolproof method, though it requires a lot of turning with the breaker bar (spark plugs removed makes it a lot easier - using the starter makes it too hard to be precise as to which lobe is where, so please do it by hand), is this:
Adjust one cylinder at a time, ignore everything but the one you're working on. Start with all the adjusters backed way off so you can see the pushrod rise, without being possibly distracted by the plunger depressing in the lifter. Turn crank until the exhaust just starts to open, then adjust the intake to zero lash (with clean threads now you should be able to find zero by turning the polylock with your fingers), then 1/2 turn preload, and lock it down. Then turn crank again until the intake has just closed, and adjust the exhaust. Repeat 8 times and you're done.
With new lifters that are still dry inside the plungers are really soft and it's harder to feel the zero lash point, but if the lifters have been run at all or even new lifters that have been prelubed it's pretty easy to feel.
If it still makes lash after doing it this way, you need to pull the intake and inspect the lifter faces. And if you don't have a magnetic drain plug you can check for the telltale silver/grey fuzzy glob that used to be your cam lobes, get one!