4AC
SOHC, carby, non-crossflow, 8-valve lump of crap, 50-60-odd kw, found in non-Twincam AE82s, and ADM AE86s
4AF
DOHC (belt-driven intake cam, slave-gear driven exhaust (maybe otherway around), carby crossflow, 16V, 75-odd kw, found in non-SX AE92s (until the change to fuel-injection