Just like the any full sized SUV...they are derived from their cousin pickup.
The 3/4 ton Suburban is derived from the 3/4 ton pickup...and they all have
modifications to suit SUV owners (more comfort than work).
Everything underneath the body. Frame, suspension, drive train, etc, etc
Though the wheel base on Suburbans are only 130"
Mine is a 1 ton (tongue and cheek), as ordered it with the F60 option ($68 bucks)
and is the snowplow prep package that begets 1 ton front torsion bars/etc...so
call mine a K3500 Sububan.
Look in the glove box door...there is an RPO code label listing EVERYTHING that,
that vehicle left the factory with