skimmer is back (with 2 questions)

Hey guys. It has been a while since I've posted to or enjoyed reading this newsgroup. I hope everyone has been well. There are too many posts for me to
catch up.
Mid summer....I bought an inboard skiboat (yes, 5.7L Vortec) and have been enjoying lots of time on and in the water. Season has ended....although Wednesday the high will be 91 here in Hot, Texas. (I might be sick that day and not make it into work.)
Since I'm back to regular biz...thought I might check in with you guys and get some thoughts on some of the repairs required for the 99 Tahoe before it gets cold, drizzly, and duck season.
1. I've had trouble starting cold. Often requires a long crank and / or wait for the fuel to prime. A couple of times after cranking and not running it has dieseled and smoked out the evap canister....scared the crap out of everyone. I checked the fuel pump pressure near the TB and measured 55 psi while running. The gauge has a bleed valve so I vented a continuous flow into a gas can and produced a nice (but unmeasured flow). Amp meter showed 8 amps. I believe the pressure is bleeding off at night. What is the next step to figure this one out? How do I tell if fuel is pooling in the upper intake or an injector is leaking? Can the pressure bleed off back at the pump or through the return? I'd like to get this one fixed before it strands me.
2. Also, I'd like to change the fluids in the front and rear diff's and the transfer case. Can anyone tell me what fluids are required for each? My Helm book tells me the capacities...but I can't seem to find the fluid descriptions and whether or not any additives are required. Rear end is the 3.42 limited slip.
Thanks in advance for your help.
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