Like it was said before. The stock wiring harness won't support the larger fuel pump. Hard wire the pump with constant voltage from the battery using the recommend wire gauge. And the drum looking things are dampeners which, as far as i know, only cause rough idling and cruising. If you removed them put them back on.
My Bosch 044 was leaning out at 450whp because of a small gauge wire from the battery which ultimately caused me to have inconsistent fuel pressure and lean/rich issues. Also use an oem fuel sock because it sits lower in the tank just to reassure you're not getting fuel starvation.
Just food for thought. Hope this helped in any way.