1990 to 1993 the stock Ford production V-8 WC T-5 was upgraded with stronger 3.35 gear set. The nickel content was increased to produce a harder, stronger gear. 2nd and 3rd gear ratios decrease slightly. Synchro linings on 3rd, 4th were improved by changing to carbon fiber to further improve shifting. Longer throw shifter was installed to "easier to shift". Torque rating jumped to 300ft/lbs.
so yes it appears it was a WC