they did put chevy v 6 engine in the year camaro you have . They called it a 3.8 also. It was 229 cubic inch. the buick was 231 cubic inch. The bell housing bolt pattern is different on the buick from the chevy.as well as the exhaust,radiator ,motor mounts, etc ... I could go on for days.
I would also like to add that NEITHER ONE was any kind of performance motor. They ran the car up and down the road thats about all I can say.
You would be much better off starting with a chevysmall block and if you wanted a vintage look find an original motor mfor it.Good luck