400 sbc much heavier than 305?!?

[erikgto]

Hi guys,

I just got my '86 C10 swb delivered tohether with a couple of other cars.
The shipping weight really shocked me! close to 4900 pounds!!!

The truck is a 2 wheel drive '86 silverado with a 400 sbc / 700R4 trans.
Dual saddle tanks, a/c, power windows, locks, bench seat, steel cowl hood, checkmate fx bed cover.
no spare, no jack.

I would have thought it would weigh around 4.100 to 4300 pounds.

So where is this extra weight?
The 400 sbc that much heavier than a 305?
Or is it somewhere else?