Just checked my manual (96 GT) and it does say 5.0 quarts with filter (4.7 litres). If I only put 5 in the light will come on. I asked at my dealer a while ago and one of the service guys told me it's definately 6 quarts.
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66 Tahoe Turquoise Coupe
Laser Red 96GT Ragtop
Both are slow but easy on the eyes!