Two FLM Savage Ext arm kits. whats' the difference?

[Finnster]

Ext arm kit:
*Machined from billet 6061 aluminum
*Extended .500" per side for improved handling
*Extra hole was added for shock position
*Lifetime warranty on driveshafts

XL Ext Arm Kit:
*Machined from billet 6061 aluminum
*Extended .500" per side for improved handling
*Extra holes added for shock position
*Lifetime warranty on driveshafts

The desc is exactly the same. price is same, picture is same.
Part #'s are different, as is title.

The only diff I can think of is the dogbone sizes, where the flux and XL have the larger ball. Pix are same, so its just a guess...

Is there no longer ext kit? Ideally a 1" per side ext os what I'd like to see. Also, how do the LST shocks mount? I don't like the way they mount on the plastic arms, with long 3mm screws hanging away from the arm. The tend to take a lot of force and bend rather easy.