diff gears
 

I have a 1983 300sd i just put into dd status the engine sounds a little busy at 75 mph.i understand no overdrive in this tranny? is there a different rear end gear available? ive seen a 3.07 and a 3.46 and a 2.40 what car would i find the 2.40 gear in?pull-a-part is my favorite place..: