2000 chevy 1500 5.3 fuel pump
 

can the pump be replaced alone or does the entire assembly need to be swapped out? if so which pump can be used? a part number would be greatly appreciated. thanks for any help or advice you guys can offer.

most typically sold as an assembly.

If anyone is looking I found a few of the bosch pumps for 155. Each vs 398. They are on amazon.com. I believe there were only 2 left after I ordered one.