Mercruiser 1.32 ratio behind a 250 hp SBC?

[tango13]

Hi all,

I was installing new decals on my mercruiser outdrive this spring and noticed a few things that are not adding up:

My outdrive has 1.32 stamped as the ratio, has a "250" hp decal, as serial number reads 4734559 (the 3 might be an 8, not 100% sure).

From what I was reading up online (on SEI's website), the 1.32 ratio only came on 454 applications, and the 250hp merc was only made in 1977 and was a 1.47 ratio.

I'm starting to guess that this outdrive is not the original, as I previously assumed. Im guessing its a donor outdrive that someone slapped a 250hp decal on? The boat is a 1978 so it is possible that it orignally had a 250 setup, but now I'm not even sure whether the engine is a 350 or 305, as it no longer has the decals on the valve covers. Who knows if the engine is even original at this point :wacko:

Is this less common gear ratio going to haunt me down the road?

 

[Scott Danforth]

if your boat is light, it may have a 1.32 ratio.

the old 350's would have been ~250hp at the crank or about 220hp at the prop

early in the MC-1 lineage the 1.32 ratio was also behind ford motors, long before the BBC and the alpha