The 1000 Hr on my 500 HP CATS was $4500. I'm sure the engines in a 58 Viking are a good bit more. FYI the 43 Post cruises 24 kts at 70% load...
I wish I hadn't added it up but was curious since you raised the question. We have an older (1989) 43 Post but with newer (now 5 years old) CAT...