They have the relay kit in the 2nd gen dodge catalog. That's why you probably can't see it on their website.

Item 55-9505
http://www.lmctruck.com/icatalog/de/full.aspx?Page=65

The idea behind the relay kit is to supply better power to the bulbs. The stock system supplies power from the batter via small wires, which then has to run all the way to the headlamp switch which controls the ground side of the circuit. (a silly idea as far as I am concerned....) That's a fair piece to travel over the little factory wires.....

The relay kit has the headlamp switch controlling the relay. You have a fat wire from the battery, to the relay, and from the relay, to the lamp, and then another short, fat, wire going to ground. The result is, you get better power to the bulb, so, it simply works better. (brighter.) The folks that have them love them. The difference is noticeable.

I wired my own. But they are at least 3x times as bright.

Adding this relay harness to my to do list. Thanks guys

i will order one up as well. is it plug and play?

The guys with sport model trucks will need 2 harnesses, LMC numbers 55-9505 and 47-3662 for both sets of headlights. All non-sports only need the 55-9505. The harnesses will be PNP, but it is only JUST long enough to get to the passenger side, so be careful how you route it. I found the ground wire to be just barely long enough to reach a factory bolt on the passenger side as well. My 55-9505 (for 9004's) came with yellow sheething (who OK'd that??) so I cut it off and used wire-loom instead. 47-3662 came with black but I still loomed it. Decent stuff for the money, just make sure to have the dielectric grease handy

Thanks for the info.