my truck is an automatic, if i leave it in drive will it allow me to pull the harmonic balancer without the crankshaft turning or should i just remove starter and lock up the flywheel?

presently i have the rotor pointing at the number one terminal and have the harmonic balancer set a 10 degrees btdc. i should be in timing. after i remove the balancer, and remove the cover, if the crankshaft has moved how will i get it back in the correct position before i install the new chain and sprockets?
any help you guys can give me would be greatly appreciated. thank you very much.

 

There are marks on the cam and crank sprockets, you just line them up.

 

No way to lock motor with an automatic. Convertor will always slip.

Like mentioned, there are timing marks on both crank and cam gears. Line them up and it will be fine. Simple. As long as you don't loosen distributor it will still be fine.

 

If you can get to the flexplate you can have an assistant use a flywheel holding tool that engages the ring gear. Otherwise there is no engagement in an automatic when the pump isn't turning. The crankshaft is keyed so the gear will go on only one way.