Specifications? We don't need no stinkin' specifications! Mechanical lifters need to be set with the engine stopped, and up to normal operating temperature. Once the thermostat opens, there's enough hot coolant in the block to keep the block and head at a pretty steady temperature long enough to get an accurate adjustment.
For a cold setting, get the cylinder at TDC on the compression stroke, tighten the adjuster to just eliminate the slack, back up 1/4 turn, and lock the nut. Run the engine to operating temperature, and do a hot adjustment. Argue about it, rationalize all the cold-setting methods you want, but you'll end up doing it right eventually.
Jerry
