Yes and no.
First, yu need to tear the whole motor apart, measure everything, then machine everything
Then after the machine work is done, buy parts
However, finding a running motor would be cheaper
I would worry about finding the exhaust manifold for a 2.3 before I spent any money on the motor
If the boat is worth spending money on a new motor, you may want to consider finding a complete 4.3/Mercruiser setup and swap in