Interesting...I have deained over nine quarts from that engine, and can replace about 8.5 on first pass, then, top up with another 3/4 to 1.0 quart after a drive cycle...about same as our 95.
The "7.5 quarts" (with filter change) that you mentioned is from the blue/white 1996 GTS Service Manual...repeated in the 1997 Service Manual as well. I USUALLY can get about 8.5 quarts in the 97 when I change oil and filter.
Since volume out/in varies with car and drain time m( I do this with about an hour of drain time)...I deliberately undershoot on refill, check it after a couple of run cycles, top up as necessary right after the change...then, I seem to have a stable level that holds til next change. Others' experiences may be different.