Well 7 lbs isn't much when I replaced the cast crank /6 in my truck with a forged crank version.
There's more than "+7" lbs difference there... And adding factory AC to a truck that was never previously equipped. 7lb don't mean much ...
7 lb makes a difference when I'm squeezing the starter between the header and block, moving it into position and starting the bolts. While lying on my back.