This newly designed adapter plates will allow you to bolt a Gen 3 or Gen 4 LS engine into the place where a 4.3 V6 came factory. 2000 to 2013 Chevrolet and GMC trucks use different front cross members that are welded in and do not accommodate the factory LS engine mounts. These adapter plates bolt to the LS engine and re-use the factory V6 engine mounts. CNC laser cut from .375 P&O cold roll steel. Grade 8 bolts and washers included. This is a set for left and right engine mounts.  You will no longer need to use the factory motor mount spacer plates. These are GM part numbers 15732463 (Driver's side) and 15732464 (Passenger side).