Well, in some ways I shouldn't post here, mainly because the very early 6.5L TD in my motorhome scored four cylinders and got replaced by an AMG/Peninsula engine uprated. But the new engine has (since 12/06) 11K trouble-free miles on it, and fuel economy has increased by about 15%. So I'm happy with my new semi-rat, as I was happy with the OEM 6.5L TD until it blew a head gasket and I got into its innards. While it's not a Cat 3126/3176, it's a very capable engine, and I have no gripes with either the old engine or (certainly) the new.
'94 Barth 28' Breakaway M/H ("StaRV II") diesel pusher: Spartan chassis, aluminum birdcage construction. Peninsular/AMG 6.5L TD (230HP), 18:1, Phazer, non-wastgated turbo, hi-pop injectors, 4L80E (Sun Coast TC & rebuild, M-H Pan), Dana 80 (M-H Cover), Fluidampr, EGT, trans temp, boost gage. Honda EV-4010 gaso genset, furnace, roof air, stove, microwave/convection, 2-dr. 3-way reefer. KVH R5SL Satellite. Cruises 2, sleeps 4, carries 6, and parties 8 (parties 12 - tested).
Stand-ins are an '02 Cadillac Escalade AWD 6.0L and an '06 Toyota Sienna Limited.