I also thought he meant that the engine turned freely, not that he was getting the engine without paying for it.

Yes, Never look a gift horse in the mouth. Take home the free engine and go through the procedure to start it when it's in your own shop with all your own tools.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)