I parted out this car and an LT1 z-28, but that one was manual, so I wasn't 100% sure and it was confirmed on another site that I inquired.
"The 3.4 case is different, it has a different bellhousing size and a different input shaft unlike the LT1 or LS1 units. This type set up is used in the 4cyl. 2.0, 2.8. 3.1, 3.4, and the later 98up 3.8 engines, It comes in two styles early to 97 non removable bell and later 98 up removable bell. It is unique to these engines and will not fit and LT1 or LSx style engine."