P7100 injection pump

Looking for a pump for '95 Cummins 3500 5 spd
current pump has CPL 1550

also : anyone have any suggestions on what I should be replacing this with ?
any good upgrades to do while I have it out or replacing it ?
current truck setup :

1995 12V 3500 4x4 5spd dually 9300lbs
Daily work truck. Sometimes I tow 6-10k. With the 235/85r16 I barley go over 65mph.
From what I can see it's stock pump and injectors. Has #8 fuel plate, 16° timing and boost elbow (spikes 25+ holds 20) no cat, 4" MBR cat back.

Not looking to make a ton of power, little more low end / better mileage would be nice