How many hours should it take to replace the fuel pump on my Yukon XL 1500?

My estimate guide asks a lot of questions. 2 or 4wd, Yukon C1500, or K1500, 5.3L, 6.0L or 8.1 L engine? It asks number of tanks size of various tanks and type of drive shaft Basic C1500 2WD seems to be 3.7 hours labor.