It really depends on what it looks like once you're inside.
Mine was smoking badly so I know the valve seat had been done a couple to many times. I had new seats put in along with a head rebuild
by Hill Head
I also replaced the sleeves, pistons, rings, all bearing. All from Stewart Marine
, WA. I also had the injector pump
rebuilt by Northland Diesel
, Seattle, WA. It was a little pricey for the pump but I know I can trust it. All the seals
and things were from Stewart Marine
. Total cost just under $3K. I basically have a new engine
. Don't forget the oil seal
packing at the back end.
While it's out I also rebuilt the transmission
. It didn't need plates so it was inexpnsive.