Working on front axle Dana 44 84 Chevy Suburban

[62ChevyC60Wrecker]

I am in the process of working on a Dana 44 on a 3/4 ton 1984 Chevy Suburban I pulled the trigger on a few months ago; work has been pulling me away from getting it worked on. I have both sides of teh axle apart; almost done with the driver side; quit last night before the rain started; no garage. The front axle has seen water; as the 4x4 hubs, the grease looks like "super chunk peanut butter". I am replacing both u joints in the front axle as well as the spindle bearing and the "rubber boot" and the plastic washer; aka spindle rebuild kit. Now would the differential lube be just as bad, or am I thinking ahead of myself here? This truck was originally purchased by a rancher in Texas and I have a copy of the original build sheet and the dealer's cast aluminum badge is still on the tailgate. I am also going to change out the steering column and the rag joint steering shaft to install a Borgeson universal shaft. I have a "laundry list" on what I need to get done in the long term; but teh shrt term, I want to get the front axle done as well as the column and steering shaft for the short term to make it my daily driver. Also what is everyone running for K&N airfilters on a 350 with a Q Jet carb. I just have the factory air cleaner.