Front crossmember removal; lift engine out first? (kinda O/T...73+)

[Canada20]

Hey all. I'm pretty sure the answer to this is yes but I thought I'd ask anyway;

Is it totally necessary to lift the engine out of a truck to remove the crossmember. I've done a little searching on this and people seem to usually remove the engine but it seems to me someone mentioned it wasn't totally necessary. I know that if i was going to be perfectly safe the answer would be a definite "pull the sucker" but...

The reason I ask is that the scrapyard i visited today had plenty of 3/4 ton's with pretty intact front assemblies but they all still had their engines. Was kind of hoping someone would've done the work for me already and taken the engines out.
I'm going to take the crossmember from a 73+ so I can get disk brakes.

Thanks all,
Greg