lower body beretta gbb

[jonny b]

i need help i need to know is.there any diff in size or length on a lower body on a centurion beretta by western arms to anyother make of beretta gbb pistols as i want change my centurion to become a M92fs so any help or clues to how do this would be great as any where i get whole top slide with outer and inner barrel to match in black only