It’s not just the engine problem you will be facing. Even if you build the motor and get it running then you will be faced with the issues of leaking transmission seals, failing brake hydraulics, wheel bearing seals, dried out suspension bushings and dust boots, etc.
Sitting for long spells like this usually takes a toll on gas tanks, fuel lines, etc. so that is also something to consider.
They’re neat cars (2 of my cousins owned them back in the 60s and a high school buddy of mine had a Turbo model) but this one sounds like a complete restoration project. Your enthusiasm for it is fine but the checkbook has to match that level of go-get-em too.