The whole engine rebuild kit cost about a $1000 it has all the seals including the coolant ones. If you can rebuild it yourself that is how much it will cost you, but if a shop does it for you like Maztech, Jeff charges $2700 includes parts and labor. You can also take the motor out and bring it to him he will charge like a $1000 less. It runs bad because water enters combustion chamber. Email me and I will give you my location, phone number and some better pics.
Thank you