One of the guys that has a dog that plays with mine @ the dog park is a salesman for an aftermarket truck supply company.
He tells me that he has access to LED headlights in the same size as the quad seal beam units in the early GMT400's.
Two versions. With or without a fan built into them. Why a fan? Apparently the LED's run extremely cooler than regular lights.
They burn brighter when they're warm. On an average vehicle, in average conditions, they heat that the lights do produce is sufficient for them to reach their maximum brightness, but the trucks used up north in very cold conditions, require the fan to circulate the heat from the vehicle to supply the heat for the bulbs to reach their max. potential.
But...here's the kicker.
$275.00 per light with no fan!
$325.00 per light with the fan!
That's $1100.00-$1300.00 to outfit a GMT400 with these!
Cough, cough, cough, cough, cough!!!!!!!