'93-95 Lightnings were the old style, with 351Ws. They had 240HP/350tq, ran mid-low 15s.
The'99-00 Ls had 5.4L engines, eaton s/c's, ran mid 13s to mid 14s (huge range with differing elevations/temps, etc). The '01+s have higher gear ratios, larger MAFs, 20 more HP. They run about .2 faster...