376336 is the casting number, which is what you can find on the part. 592984 is an ‘engineering’ part no, different because the head includes a couple caps on the central tube, hence an assembly. Other than a parts list, the only place you’ll find that number is on the box it comes in..
The two numbers will usually coincide if the part is a simple (no components) part.
Marineengine says they have a new one cheaper than Ebay
