So im sick of double cranking my truck so im gonna replace the fuel pump. I have a 99 cherokee XJ.

I work in a body shop and pulled up the R&I on the pump on ALLDATA. It says that the plastic cap NEEDS to be replaced when you replace the fuel pump. Is that REALLY necessary?

Also a tech at work has 2 Walboro fuel pumps, bran new. I compared the actual pump with pictures online(his pump is for a mustang) and the pumps themselves look identical, if i can get away with not spending $100 that would be great.
Has anyone else used a generic fuel pump? And is it really necessary to replace the cap/grommit?