camming a 4.6

[HOOLS96GT]

hey guys hows it going.well my crower cams stage 2 and crower valve springs all came in the other day. i am a ford tech at a ford dealership and i have installed many cams in 4.6 5.4 6.8 and never have had to degree them. i got my crowers in the mail and there was some directions in it saying that you should degree the cams. now my question is why degree the cams if the cam gear is keyed to the cam and the crank is keyed to to cank line up the timming marks and run it. i mean thats how ford taught me in school but ya this is the after market world i know but is it really that different?
thanks any help would be greatly helpful.
1996 gt pi conversion ported polished 3angle valve job cl intake 80mm maf 75 t-body pulleys 24 injectors adjustable reg 255 pump stubby headers x pipe 373's cobra brake conversion lowered king cobra clutch shifter cobra r's