Any problems with 3.0 V6 Mercedes engine on Class B Van

HEY WE HAVE ONE . the last of the I 5 MB diesels. in a leisure travel van. BEST MH we ever owned. I,ve had class A,B C TT,TC and this is the best of them .my log book shows NOTHING under 20mpg . theres some out there just gotta hunt. BUT I to have been told the 5cyc is much better than the V6. and this came from a fed X mech. theres a club flamingo,S something in florida there on yahoo site some times I see one up for sale.