I took my truck to a retired Chevy mechanic to have a new lower ball joint put on. When I went to pick it up, he said that if he would have known it was a 1500 with heavy duty suspension, he would have charged me more than $70 labor. He said he was a little suprised to see HD suspension on a 2004 Silverado 1500 2WD. So....my question is.....did they really make 1500's with HD suspension and if so, could there be the possibility of having something other than the 4L60e transmission. I didn't think to ask him at the time. Oh yeah, it's a 4.8 liter.