What is the difference between Mercruiser #1/R and ALPHA 1 outdrives

Rockyncali

Cadet
Joined
Apr 6, 2004
Messages
17
I have a defective upper and lower unit 1969 Mercruiser pre-ALPHA. After checking the price on iboats I'm at the point where I finally saved the money to get my complete unit replaced. Then I did research before ordering my unit. I found out that the only difference between the 2 is the angle in the gears in the lower unit and something about the water pump. Is this true? or was I given bad info? I'm ready to make my purchase and honestly I would rather upgrade to a alpha which I was told is much stronger than a pre-alpha. If anyone knows the truth it would be a great help. Like I said I would love to get a better unit but only if it will bolt up to my gimbal. Also if it will bolt up, what's the deal with the water pump?<br />Thanks for your time.
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: What is the difference between Mercruiser #1/R and ALPHA 1 outdrives

The MR and first generation Alphas are very similar. There are different kinds of driveshafts into the lower gearcase, so it can make a difference which lower unit you put on what top end. Newer generation Alphas have different water pumps than their older brothers, but they operate the same. Alphas with those water pumps aren't mountable to older uppers. Later ones had speedometer pickups built right into the lower gearcase, but they changed the hose connectors a few times already. Mixing uppers and lowers is definately tricky.<br /><br />Now the good news. As a complete drive, they mount just fine to the boat, even to the older pre-MR mount. Only hurdles are the driveshaft into the motor and the speedometer hose connectors (you won't need to worry about that one). Oh, and the fitting for the oil reservior, but that can be removed and plugged.
 

steve n carol

Chief Petty Officer
Joined
May 8, 2004
Messages
459
Re: What is the difference between Mercruiser #1/R and ALPHA 1 outdrives

willy, that was the BEST answer I have seen to this question. This was very similar to my first question on iboats. thank you!..sl
 

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
Re: What is the difference between Mercruiser #1/R and ALPHA 1 outdrives

Rocky... Take a look here... Drive ID
 

Rockyncali

Cadet
Joined
Apr 6, 2004
Messages
17
Re: What is the difference between Mercruiser #1/R and ALPHA 1 outdrives

Thank you for all the help. The speedo hurdle, you're right I don't have to worry since I'm using an add-on unit anyway. As for the drive shaft to motor hurdle I'm guessing you mean I might have to use my old yoke? I have no problem with that, if it comes up.
 
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