On Sun, 22 Jul 2007 14:11:32 -0700, fireguy
wrote:

I recently bought a 1987 Rinker 250 with Mercruiser Alpha One 260 (5.7
liter). There are no markings on the existing prop, but it appears to
be almost a flat prop - no cupping. The performance is poor, but WOT
is about 5500 RPM. Looking for suggestions for a new proip, or at
least a starting point. I don't want to spend thousands of dollars to
dial it in.

Clean the inside of the prop of exhaust residue and the size and pitch
will be stamped where the prop hub meets the shaft spline.

I think you might want to drop the rpms a little - that seems awful
high for a 350.