Assassin bars

I'm not sure it would ever need either. LOL I have XHD +2 springs on it now.
But just for fun if you wanted to spend$400, then the assassin bars will work for ya, I think caltracs are cheaper for standard spring location. I bought these for the good reasons stated & they're a bit cheaper than the inboard spring caltracs. Maybe $20 bucks or so, but I'm sure I'll be happy with them.