I'm soon to be getting a narrow beam for my 69 panel .im thinking 4" narrower.i like the look of the weedeater as it has adjusters to lower it to although I have 3.5" dropped spindles fitted so it won't totally rely on them .
I can't answere that question but if you go for "4 you will probably have to narrow you lower arms ( remove some material from where the bottom shock mount locates into the arm) so that you can space the whole shock away from the beam, or have lift arms fitted.