I just picked up a 180K not to long ago. It has a c204/90DBC-0. It had 33 years and 785 hours SNEW. The overhaul and SB convert to oil filled was $2900. Maybe in the next year the 470-U will become a 470-50 with a mac 401. At that time this one will go to a new home.
John

That's a helluva good price for an overhaul if it included the oil-filled-hub conversion per SB.
Mine was a lot more, like close to $4K.

I just pulled my ticket. it was $ 2,677.22 with the oil fill conversion SB done. It was even delivered close by. I met a travailing IA at an AG operation an hour from me. The shop is First Flight Propeller in Senatobia,MS. I have some friends in the AG business that recommended him to me.
John

You could also try Texas Skyways O-470U/TS STC to increase the redline RPM. Achieves 250 HP. Maybe your current prop is even eligible.