[N2TRUX]

Welcome to the forum 78-5.3. Looks like you have a pretty good start on a nice project.

Since you no longer have the additional weight of the diesel motor to contend with, standard lower practices will apply. The only thing you don't mention is what size/height tire you plan to run.

For the front I suggest going with 3" dropped spindles. A common practice is to cut one coil off of the stock spring to get 1.5-2" drop. I don't know what spring was used for the diesel trucks so your results may vary.

You can also replace the stock spring with an aftermarket drop spring if it's in your budget.

For the rear you can either run a shackle and hanger kit, or go with a flip kit.

The shackle hanger combo usually nets 4' of drop but your HD spring pack might minimize that somewhat.

As you mentioned the flip kit is the best way to go. You might have to notch a bed brace depending on what spring and wheel base you have.