You should be able to jumper the lift pump. There is a jumper wire on a 98 in between the under hood fuse box and the firewall.
It is just a little wire with a male or female spade connector. I have been installing a toggle switch with an inline fuse coming off the under hood fuse panel - to that wire on 1996 and newer 6,5's
95 and older need the lift pump relay upgrade.
What brand of lift pump did you buy? If going OEM style - use only a GM or ACDelco. I had no longevity out of any other brand.
A permanently mounted fuel pressure gauge is a very handy thing to have for diagnostics.
Did you test the new pump before installing? New does not mean working - always test new parts before installing them.
I know a guy that installed a new fuel tank sending unit without testing - that's a time waster right there. Same guy also got bit by new but bad seals, bearings, alternators and starters. You'd think he'd learn to test everything possible before installing, but I still forget sometimes.
Jumper the little wire by the fuse box - or just go ahead and install a fused toggle switch as I do for diagnostics and bleeding the fuel filter - or you can go whole hog and get Leroy's lift pump relay upgrade.
The upgrade is not really necessary on 96 and newer, but the heavier wiring certainly does not hurt anything.
Do not change the OPS unless you verified it is bad. To much of a PIA and new parts are not guaranteed to last any longer than your good working old part. I do some parts swapping without verifying, but for the most part I avoid it.
Parts swapping I do - If I have the intake off - I give the engine harness and IP harness a visual. If they look suspect, I just install new harnesses. I am about done with that now. I think I have 2 vehicles left that could use new harnesses.
