hello i have been offered 2 engines one being a 2001 from a trans am and the other being a 2004 from a gto what would be the difference? also what difference is there between a 3rd gen engine and a 4th gen engine?
thanks
matt

 

Both engines are the same. A Gen3 engine would be an Aluminum LS1 or LS6 (both 5.7L), as well as the 4.8L/5.3L/6.0L iron engines. A Gen4 engine would be an LS2 (6.0L) or LS7 (7.0L) which are both Aluminum, as well as the L92, L76, LS4.