Valve Lash adj. question
You can either turn eng manually or click starter with remote or have someone in car do it while observing the rocker arms.
You can also use a degree wheel to set each cylinder. Use 90 degree increments.
As for rotating the engine, I wouldn't use the starter method. You'll overshoot
almost everytime.
Get some sort of crank adapter and use a torque arm to rotate the engine.
Whatever it takes to get a positive grip on the crankshaft snout.
I don't know how easily the crank bolts strip on LSx motors, but if you're
in a bind, remove the spark plugs and pulley drive belts.
Set a torque wrench to about 5 lbs./ft. over the manufacturer recommended torque.
If the wrench clicks, the crank bolt is tightening and could strip.
Stop turning via the crank bolt.

