Early Mercruiser I/O Question.

[VenturaCobalt]

I am new to the forum and have recently purchased a very nice, one owner 1972 Cobalt 16'4 with a Mercruiser 140 I/O. I have two out drives that are "pre-Alpha" and I was wondering if anyone could tell me exactly what they are as it is a bit confusing prior to the Alpha line. The serial number on the drive that is on the boat is 3287079. The lower unit of this outdrive is a bit nicked up however. I do have an additional complete outdrive with S/N 2944299 as well. Any advise as to what the two drives actually are and weather or not the lower unit of the second drive can be used with the fist drive would be greatly appreciated. Does either s/n represent a better choice? Any opinions on older Cobalt boats.....seems to be a very solid nicely designed hull? These forums have always been a huge help, I thank you all in advance for your input!

 

[Bondo]

I am new to the forum and have recently purchased a very nice, one owner 1972 Cobalt 16'4 with a Mercruiser 140 I/O. I have two out drives that are "pre-Alpha" and I was wondering if anyone could tell me exactly what they are as it is a bit confusing prior to the Alpha line. The serial number on the drive that is on the boat is 3287079. The lower unit of this outdrive is a bit nicked up however. I do have an additional complete outdrive with S/N 2944299 as well. Any advise as to what the two drives actually are and weather or not the lower unit of the second drive can be used with the fist drive would be greatly appreciated. Does either s/n represent a better choice? Any opinions on older Cobalt boats.....seems to be a very solid nicely designed hull? These forums have always been a huge help, I thank you all in advance for your input!

Ayuh,.... Welcome Aboard,..... There's Lotsa Great info on the Alpha lineage up in Don'S Adults Only section, at the top of this forum,.....

My guess is yer drives are Mod. 1s,.... If the gear ratio, in the Upper units are the same, they oughta swap, drive for drive, no problem,....

If the ratios Are different, the lower units will most likely swap with each other, the Gotcha is the spline count of the input shafts,...
The spline count changed alone 'bout that time,...

Pull the drives apart, 'n check the splines,...
If they're the same, ya got 2 lower units, 'n maybe 2 upper units, dependin' on the gear ratio,....
If the splines are the different, ya got 2 complete drives, that'll swap drive for drive, dependin' on the gear ratio,......