Yes, the first two years the GT40 had the 427, then they went to the 289.
Don’t want to be a butthead but you got it bass akwards. The early ones came out with the 289 but they went to the side oiler NASCAR 427 and it is the gt40 that won the first of many Le Mans, as well as others, races for Ford. The FIA, at the behest of Ferrari, much later reduced the max to 5 liters.