Yeah, I knew the 88 was molded to the tube assembly, that why I was hoping the tube was the same as I'll just swap the whole tube, keeping the forearms themselves intact.
Edit: Nevermind, I'm an idiot....I was just thinking, all I want off the 88 is the mag tube and barrel. So just swapping them out with my 500 will work. It's been a long week, not sure what I was thinkin' earlier.