Help identify Mercruiser drive #

tmh

Lieutenant Junior Grade
Joined
Aug 16, 2006
Messages
1,136
Hi. I have a re-power project going on and have asked many ??? so far. Here's the latest. I am pulling my 1985 merc 305 5.0L engine (has Alpha one drive). I am trying to find another boat to put it in. I see some for sale without engine or outdrive so i may or may not need a drive as well.

I see listed a mercruiser outdrive the seller says is an Alpha off a 4-cyl engine. he lists the serial # as

"Serial # A 420915 with an F on the side".

Where can I find a cross reference sheet to find out just what drive this is? If Alpha One like mine, would I need one from a smlilar V8 powered boat (gear ratios different, i think).

Thanks.
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: Help identify Mercruiser drive #

Can't help you with the # but, the gear ratio in the upper is roughly 2.0 :1 for a four cyl. & 1.50 for an eight cyl.......
The lower should work on either gear ratio provided the are of the same vintage......;)
Don S has a way to look up the specifics, I'd look fo his reply......:)
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,447
Re: Help identify Mercruiser drive #

If Alpha One like mine, would I need one from a smlilar V8 powered boat (gear ratios different, i think).

Ayuh,...... You've got It,..... That's pretty much the way it Works,......

Gear Ratios,+ Vintage are the Keys.........
 
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