Mercruiser MC-1 1.32 Drive

[San_Diego_SeaRay]

Serial Number: 6267140
Ratio Stamp?: H

So I have this sterndrive that I bought a few years ago. Back when I bought it I didn't know any better and was told it was an Alpha Gen 1 drive w. a 1.5 ratio. I brought it home and put it in storage (I bought it w. a Merc engine and it was the engine I was really interested in).

So I recently called Mercruiser Customer Support and they told me the serial number maps to an MC-1 drive with a 1.32 ratio.

However, after researching, it seems that the 1.32 ratio was a rare bird. I can't find much on them. Also, it seems that MC-1 drives had rounded anti-cavitation plates and a top with a hole in it for lifting. Mine has a squared anti-cavitation plate and a traditional Gen 1 top with no hole for lifting.

My questions:

• Can this drive be bolted up to any Alpha Gen 1 application (ignoring the ratio issue)
• Does anyone know why there might be a discrepancy between Mercruiser saying this is an MC-1 and the rest of the internet saying it's not? Did some MC1 drives look like Gen 1s?

 

[achris]

Serial Number: 6267140
Ratio Stamp?: H

So I have this sterndrive that I bought a few years ago. Back when I bought it I didn't know any better and was told it was an Alpha Gen 1 drive w. a 1.5 ratio. I brought it home and put it in storage (I bought it w. a Merc engine and it was the engine I was really interested in).

So I recently called Mercruiser Customer Support and they told me the serial number maps to an MC-1 drive with a 1.32 ratio.

Nope, that serial number is very much in the 'R' range...

However, after researching, it seems that the 1.32 ratio was a rare bird.

Indeed. Usually only hooked up to the bigger Ford engines (233 and 250 HP) or the 454 (for a short time).

I can't find much on them.

Nothing special except the tooth count in the top box. Everything else is the same.

Also, it seems that MC-1 drives had rounded anti-cavitation plates and a top with a hole in it for lifting. Mine has a squared anti-cavitation plate and a traditional Gen 1 top with no hole for lifting.

Yep, that's the configuration of an 'R' drive (also MR and Alpha One, but your serial number is 'R').

My questions:

• Can this drive be bolted up to any Alpha Gen 1 application (ignoring the ratio issue)
• Does anyone know why there might be a discrepancy between Mercruiser saying this is an MC-1 and the rest of the internet saying it's not? Did some MC1 drives look like Gen 1s?

1. Yes, directly bolts up to an Alpha one bell housing.
2. :noidea: maybe the person you spoke to read the serial number chart wrong, or misheard you... No, all MC-1s look like MC-1s. And not like Alpha Ones.

Another check that will confirm 'R' is to split the drive and look at the top of the lower drive shaft. It should have a pre-load pin.....

Chris.......

 

[San_Diego_SeaRay]

Thanks Chris! That pretty much sums it up...