I believe almost any V8 will fit with little to no sheet metal modifications.
As Spanky said, Chevrolet used the 265, 283, 322 and 348 in the 55-59 LCF's.
Shane installed a BBC in his 1957 LCF, check it out here;
https://www.stovebolt.com/ubbthreads/ubbthreads.php/topics/940994/1.htmlI have a '56 9200 LCF that has the 322 and Powermatic 6-speed Allison automatic.
Mike B
