It's a 5.0 (305).
All 91-92 civilian Caprice were 305's.
The TBI 350 was only available in 9C1's and 1993 LTZ's.
As long as you don't mind driving a complete dog that handles like an old Cadillac, then it may be a good deal for a reliable DD.
Solid TBI cars can be had for $1000-$2000 all day though.