He wants a double-arm for cross-over-ish steering...not stock arms. The only places I have seen them are Aqualu, All-pro, and Marlin...maybe Extreme Gear had them. Not sure what years and what-not...just call them up and see. Most of these places started off with stuff for Toy Mini-trucks and with the mini-truck knuckle steering arm bolt pattern being the same as later years LCs, they just started selling the same ones for the later years LC applications. Anyway, just call them.
Also, the only place I have noticed that for sure sells anything like that for the older LC knuckles is Rockbuggysupply.com. But it's a complete high-steer setup. Pretty dern good price on it though....only $100-$150 more than any double-arm I've seen. Only draw back is it uses GM TREs (if that's really a draw back...).