i am not sure if the 3.4 in monte carlo's have them but noticed it on my sister buick rendezvoue

3.4 oil cooler uses coolant and an adapter into the block

goes block/adapter/filter

The oil flows throught one layer of the aluminum adapter(inner) and your coolant runs throught the another (outer layer) of the aluminum adapter

there is a nipple that has to be put into the block(there is a plug there and quiet posibly need to put a different pipe that comes off the water pump

but i thought this was kind of cool and might be a good upgrade to keep oil temps down/at a decently regualted temp, for people with the 3.4 if the monte doesn't already have it already , i will get pics of it when i work on my sisters buick again and show really what i'm talking about