No right or wrong answer to that.
If it worked before and didn’t leak, there’s a better than average chance that it’ll work fine and not leak right now.
You can always pressure test it yourself somehow, using gentle compressed air. Or you can take it to a radiator shop they usually test it for a minimal fee. And can fix it if needed.
Or you can install it and see if it leaks. Most of us have probably done all of the above at one time or another.
Even with a mild cam (how mild?), as long as the engine is tuned properly, it shouldn’t develop so much more heat that the radiator can’t handle it.
Not to say there aren’t plenty of good options these days. Just that if I had a stock one that was still in good shape, I’d be very inclined to reuse it.
