If you have the bronze, it will work also.

The advantage of the treaded fittings is that they can be pulled easily -- though I've nerver had a Shurflo pump fail. Maybe I'm lucky. Ther first boat had an old Par reciprocating pump which I got tire of rebuilding for close to the cost of a Shurflo. the Shurflo lasted another 7 years until I lost track of it when I sold the Sabre. The J/160 had a PAR pump. After two years, I chucked it at the first sign of problems. The current one is into its 12th year or more.

I too, looked at the plastic as weird -- but it works fine, doesn't corrode, etc.