Super Chevy article adding headers to a crate motor LS6, gained 25hp with the tune.
Chevrolet small block is the most installed engine across the world, PERIOD. So whether you like them or not, they have a large footprint in the automotive world. The craze for at least the last decade is junkyard pullout LS motors and the truck equivalent 4.8, 5.3, 6.0 and 6.2 liter engines. The aftermarket support for this engine series is probably 2nd to none, if you know of one larger, let me know.
Click link for boosted 4.8 HOTROD
With regular maintenance, these motors will outlast the rest of the car.
My current personal favorite is the LS series motor is the LS6. Good platform in stock form, makes good power all over and reliable (except for the valve spring issue on production 01 Zs and 02s) and make good power with cam and headers.