Cummins VT 55M 2240 hrs

Ask just about every Trucker hauling for a living and they will tell you how long lived these units are.

The real problems are the usual Cummins ones of stupid placement of the Sherwood water pump and getting to the aftercoolers for cleaning. A good pair of VT's that have had good care are nothing to worry about, plenty of cheaper spares about from the truckers too.

I think you are talking about the Cummins VT 903 series.? Super on highway engine, legendary for souped up trucker rigs. Still used by US army today. Good track record in marine, but just as long in the tooth as the DD 2 cycles.

The triple nickel 555 series and the lesser 505 Cummins did not deliver the same in the Marine field. At 270hp the 555 is probably better than its big cam 325hp version, but both would be an ideal repower with newer Cummins recon engines. I personally would not drop a penny into the old 555 engines.

you can search boat diesel .com for info on these engines and turn up what their likely maintenance issues will be.