Find the specs.
Doesn't it have a gauge or a light for oil pressure?
The 383 has an external oil pump on the side of the block.
They do fail sometimes. (shaft drive for it can fail too.)
They can be changed easily.
They are also known for wearing out rocker arms causing excessive clatter and breakage because they do have a tendency to starve for oil on the valve train if things are not completely kosher.
Another thing.... Can you tell the difference between an exhaust manifold
leak and Valve train clatter? they can sound somewhat the same.
Serious, you have to be careful what you do here.
If you get oil pressure cranking with a gauge on it then pull the valve covers if you want to see what is really happening.
Any more advice is $95 per hour because this is what I do for a living.
Take it to a shop before you get in over your head.
Your scaring me.
A “rebuilt engine” can mean anything or nothing when it comes from the mouth of a seller.
EXCELLENT ADVICE!! With a car of this vintage, you don't want to mess up something that could be easily fixed by someone who knows what they are doing. If you were tinkering with an old Pinto, I'd say do it yourself - if you mess up - small loss but with a classic '70s muscle car - I'd recommend you bring in some expertise - you don't want to screw this up.
I plan to follow my own advice. I have a Ford 427 side-oiler block in my garage. Once I find something worthy of putting it in, I'll have the engine rebuilt. I tossed around the idea of rebuilding it myself but decided that I didn't want to screw this up.