Re: short to long shaft conversion.
Absolutely not.<br />The 9.9hp and the 9.5hp are two totally unrelated engines. Likewise, their extensions are very different. But that makes me wonder since you say they look similar. A 9.5 L/U is held on by 4 bolts while the 9.9 is held on by 6. What I mean is they shouldn't even look close to the same.<br /><br />Hope that helps!