Valve Lash - Hot or cold?

Remember-setting the lash hot doesn't necessarily mean doing it while it's running. Like Halifaxhops said- that's a Chevy thing. Just warm the engine up well and then set your lash.
And use the procedure outlined in the factory service manual (I won't rewrite it here- just look it up)- there's a difference between "just getting it running" and getting it running well.