Greg Snider just posted that his regular cab dakota with a hellcat engine (yes, you read that right...) and T56 transmission weighs 3764 with 3/8 tank of fuel. Front axle is 1106 and 1193, rear is 711 and 754.

My extended cab dakota with the V6 and a powerglide is 3994 with a half tank of fuel. Front axle is 1142 and 1098, rear is 854 and 900.

That is 230 pounds of difference, give or take a little discrepancy in fuel ballast. His supercharger is 100 pounds by itself, not sure how the hemi block compares to the 3.9 but I would imagine 30ish pounds difference of material and fluids. My powerglide is 90 pounds wet, which is wayyyyyy lighter than a 42RE. So call the chassis about 300-325 pounds different.

 

Mine weighs about 4,300 lbs.

 

You have covered all the normal maintenance items. There might be room for improvement, but there are too many variables involved.