I own two 261s both have the captains bars, also have a 1953 235 Passenger car 235 from the powerglide equiped car, it has two captains bars identical to the 261s. Have also read of 261s with a single bar or now bars at all. Casting number should be below the fuel pump and just above the pan lip, usually packed in crud and must be dug out to read.
My 55 first series 261 is as follows- original green paint, high water pump like the old 216s, has the motor mount bosses on the sides like the passenger car motor but not drilled out.
