I thought I'd try this prop as a spare, and was test fitting it, and there is no way this can be right, yet I have all the right numbers according to the mfg web site. This is on an 2007 Alpha 135 3.0 sterndrive, and is a 21 / 14.25 RH prop.
I have the H1421 and the 31 hub kit.
The OEM prop...
