New boat-Need info on Mercruiser Outdrive Model Number

C

cheburashka

Senior Chief Petty Officer
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May 28, 2005
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I just picked up a '71 Glasply with a Mercruiser outdrive. The only markings are "Mercruiser" and 120-130. The serial number is 3696300. The current prop has some chunks missing and I would like to replace it. Prop number is 48-58424A4 21P. I'd appreciate any information on what this outdrive is (Alpha? Bravo?) and whether the prop numbers have any significance related to size or what outdrive they fit.<br /><br />I appreciate whatever information you can provide.<br /><br />Thanks
 
Don S

Don S

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Aug 31, 2004
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Re: New boat-Need info on Mercruiser Outdrive Model Number

It's a pre Alpha drive known as a Mercruiser One drive. Similar to an Alpha, just a whole lot older. That 48- number is the Mercruiser PN for the prop. The last 3 letters indicate the pitch of 21" the rest of the number indicates the diameter, and model and material of the prop.
 
Bondo

Bondo

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Re: New boat-Need info on Mercruiser Outdrive Model Number

Your Drive uses the Same Props as it's sister drives,....<br />Alpha 1,+ Alpha GenII.....
 
Bt Doctur

Bt Doctur

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Aug 29, 2004
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Re: New boat-Need info on Mercruiser Outdrive Model Number

not sure of the changeover date ,but the early ones had a "coarse spline" .you cant use a late model upper or lower because they use a "fine spline" for the lower drive shaft. you can replace the whole drive as a unit though matching the input shaft length.
 
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