Starter
Dry time it.
We do it to every engine before initial starting.
Take all the fuel away and it can't start.
Best way is before any fuel is to the carb/injection
If it has a carb and already has fuel in it, just remove carb. Pull the plugs, turn the engine over by hand (or on the starter with ignition disabled) until your sure all the fuel is out of the cylinders. Replace plugs and wires. Hook up timing light as normal and check it while cranking. Double check it after running.
On blown Hemi with magneto, we just keep the fuel shut off on the cable pull.
Then we turn the engine over backwards with a big breaker bar to push any combustable liquid out the exhaust valve into the headers. Useing a MSD self powered timeing light gets it close enough to not back fire and after running usually have to fine tune it.