Try 150 LBS difference. I did a straight axle swap and the shipping weight on the straight axle (with control arms, rotors and calipers) was 283LBS. When I sold/shipped out the IRS (springs, Shocks, Rotors, and Calipers) the weight was 430LBS on a 30LB palette. So do the math it’s about 150LB difference. (Figuring that the palette did weigh about 30LBs in both instances.)
I dont miss the IRS one bit!!