Slowly assembling my 292. I found a page a GM Tune-up page online that lists the preload as one turn past zero lash. Would this be true weather oil soaked or not? I soaked mine in 10w-30 overnight.

Hydraulic lifters only require .025"-.045" preload, which is around 1/4 turn past zero lash. One full turn will preload them too much.
Another problem with trying to use older tune up data is that the parts used 30+ years ago when these bulletins were written are no longer made to those same specifications, and that info may no longer apply to current parts made today in most cases.

I agree with CNC. New lifters are different than the old original parts. I set mine with 1/2 turn preload. Adjusted with the engine turned off.

Thanks. Headed out to put them in now.

Does that mean you have to fill them first?
Is soaking in a can of oil sufficient?
Does cam need to be on or off valve open position?
Thanks

Soaking or filling isn't necessary, but the lifter needs to be on the heel of the cam to properly adjust the preload/lash.

SOAKING IS MANDITIORY AND FIRST FIREUP GO THRU THE FIREING ORDER AND ADJUST VALVES TO 0 LASH PLUS 1/2 TURN THE WHEN ENGINE FIRES LET IT WARM UP THE RUN THE VALVES AGAIN WITH ENGINE RUNNING ,LOOSTEN ONE BY ONE, TIGHTEN DOWN TILL RATTLE STOPS THE GO 1/2 MORE TURN. DONT FORGET TO ADD ZINC TO NEW ENGINE OIL TO BE SAFE. DONE IT THIS WAY FOR 40+ YRS AND 0 FAILURES.
BOB

I did some reading in literature put out by the lifter manufacturers. They mostly agreed that soaking wasn't mandatory, but doesn't hurt either. They did all state not to pump them up though. The method I used was to follow the firing order with each cylinder at the bottom of its firing stroke when both valves are closed. This way you only rotate the crank once. I ended up going 1/2 turn past zero. It had been a while since starting this engine overhaul, so I drizzled some cam lube in each lifter port and smeared a little moly lube on the bottom of each lifter before putting them in.