I concur, no ATF in the engine. It contains friction material that could and would harm soft bearing surfaces. The gasoline has already cleaned your engines' insides, just pull the drain plug and let it drain overnight. The leftover gas will evaporate once you start driving and heating things up. For peace of mind, do an earlier than normal oil change as Jerry has mentioned,
Scott


Scott Ward

2 1948 1.5-ton Loadmasters
The red one and The snow pusher
1 1950 3100
1 1955.1 Chevy 6500
1 1954 Chevy 6500 2-Ton
1 1955 1st Series COE 5700
1 1963 K20 (454)
1 1964 C10 (350)
1 1951 1.5-ton Dump Truck
1953 and a 1956 Ford F800

Raising a teenager is like trying to nail Jello to a tree!