Heavy duty seal kits are 200 bucks. You need to remove the engine (1-2 hour job if you know what you’re doing). Then you have to take the housings apart and replace the seals. That is all it NEEDS to run. I would invest in an intake manifold gasket set or just an all out gasket kit to be safe (Comes with coolant seals). No need to rebuild. You might tear some gaskets when taking the intake manifold off so thats why I suggest that kit as well.
It could be done in a week if you take your time with it. The only reason I’m not doing it myself is because I need a grand to move to arizona so this is my only viable option since time is running out. It runs. Just gets real hot. If you’d like to take a look at it, I can charge the battery to show you it cranks and starts. I don’t know how well it’s going to start in the cold weather but it might.