Seeing if this cam is good and if it will work
Personally, I don’t think it’s a good idea to try and install HP parts into a 40-50 year old engine of unknown condition.
Especially if the motor has high mileage and has never been apart before.
Since a cam swap requires the front being removed, the intake, and the valvetrain....... you’re not that far from pulling the heads off.
Then a more thorough assessment of the condition of the engine can be done.
I’d actually do a leak down test to try and determine if there are any ring sealing issues before I took anything apart.
To put almost any performance cam into a 100% stock 318 will require at a minimum a spring change.
Be nice to be able to clean everything up(valves, bowls, chambers) before putting the new parts in.
Also gives you a chance to assess the condition of the seats and guides.
If the heads have never been gone through before, it’s likely they’ll need some guide and seat work.