Harmonics Issue, not thinking oil issue here
Oil capacity can be increased by addition oil bypass system and larger filters if one desires.
Not being an engineer, I can only guess that smaller engines I've seen mounted w/rubber bushings on things like the AC compressor, alt, p/s pump, etc are there to reduce harmonics on crank resulting in a smoother/longer operating power plant.
We see GM's attempt to smooth thing out w/balancer and lower pulley assemblies being isolated by rubber, or?, on the 6.5.
Right now we have the option for the Fluid Damper to make things even smoother on the 6.5.
I remember someone herein the forums mentioning the forces upon the crank which could lead to crank failure when there is a miss, or stumble like so many 6.5's w/DS4 IP live with; This I think is the issue!
99 GMC SUB, 2500, 4x4, 6.5 TD (F) #H32 enhanced blk, Phaser timing set, B&D IC, 3" ATS exh, K&N w/prefilter, 4WD NVG 246, 4L80E kevlar Transgo off road/tow mods/B&M supercooler, 14 FF MagTec w/locker 3.42:1, 9.25" IFS frt/diff 3.42:1 w/ARB locker, AutoMeter Boost & pre-turbo pyro meter, 12,000 lb hydro winch, Warn classic bumper w/brushguard & diesel scoop, Max E-torq Stage 3, hi pop inj, oil bypass sys, on board air comp for front ARB locker & tire inflation, DynaView driving/auto-cornering lts, DZ nerfs, A/T 285/75/16 SilentArmor 3750 lb rated on 3750 lb rated Alcoa, 3 IP drivers 2 r spares.