Q: 2000 Chevrolet Monte Carlo engine block issue

According to the re-manufacturers’ catalogs, those engines are not interchangeable. I also see on www.car-part.com that they are are not interchangeable. If you conduct a search at that website you will see that the 2000 Monte Carlo 3.8L engine interchanges with just about all GM models using that "engine type" but if you do the same interchange search on the 1996 Camaro engine, the only interchanges shown are with the Firebird and several nearby model years of the Camaro. A key issue is the block casting for the two engines are DEFINITELY different which will mean you will have trouble mounting accessories and getting the engine to fit into the Camaro.

The heads are different too, although the crankshafts appear to be identical. Your best bet is to match the castings exactly. That will create fewer headaches for you. On your Camaro replacement, you want to look for (these are your current castings that you want to match) Block Cast # 287, Crank Cast # 2170; Right Head Cast # 478, 4781; and Left Head Cast # 478, 4781. If you do select and install a replacement engine and need assistance with any fuel or ignition related start-up problems or electrical issues, feel free to contact YourMechanic for assistance.