user: Question: What is the fleet number when the transmission is Voith D863.4 and the engine is Cummins ISL?
Columns: ['Fleet #', 'Year', 'Manufacture', 'Model', 'Length (ft)', 'Engine', 'Transmission']
Types: ['text', 'real', 'text', 'text', 'real', 'text', 'text']
Sample row: ['1050-1055', 2001.0, 'Gillig', 'Phantom', 40.0, 'Detroit Diesel Series 50', 'Allison B500R']
SQL:

assistant: SELECT "Fleet #" FROM "Table" WHERE "Transmission" = 'Voith D863.4' AND "Engine" = 'Cummins ISL';