The LS architecture. It's almost identical from engine to engine whether it's an LS1, LS2, LS3, LS4, LS6, LS7, LS9, LSA, LQ4, LQ9, LM7. Size ranged from 4.8L, 5.3L, 5.7L, 6.0L, 6.2L, or 7.0L. And I'm still missing a few, that's just off the top of my head.
There's interchangable parts from every single engine I just mentioned.