You can still get the 4.3 in a full size truck. The Colorados have a 3.6 V6 as one of their options, and if it's anything like the 3.6 in my wife's Acadia, is surprisingly powerful. For a mid-size, 3 row SUV, it's a rocket.
The GenIe (LU3) 'Vortec' 4.3 made 195hp @ 5300rpm & 260 Ft.Lbs o'torque. @ 2800rpm. 9.2-1 compression. Base engine in GM trucks until '14.
Apparently, the LU3 is now only produced for the Express and Savanna vans.
Starting in '14, the GenIV (LV3) 'EcoTec3' 4.3 made 285hp @ 5300rpm, (297hp on E85) & 305Ft.Lbs o'torque @3900rpm. (330Ft.Lbs onE85) 11-1 compression.
The LV3 has a shorter stroke with a larger bore than the LU3.