Mercury 8hp Four Stroke 2006 - Lower Unit Bolt Sizes

[Rupe]

Hi - need to change the impeller on the above engine. The bolts are pretty corroded - assuming I can get them off they may end up a bit mangled and would like to replace them with rust proof ones when I do.

Does anyone know the correct bolt sizes / part number - pretty sure they were a 10mm - but that's all I have.

Thanks