Retrofit Sterndrive for 1972 Mercruiser 120/140 I/O

[72StarcraftChieftain]

I understand that at some point mercruiser corrected that problem that plagued the 120/140 series sterndrive with their upper bearing failures. I've seen them for sale in the past but have been unable to locate them recently. I'm rebuilding my 1972 StarCraft and if I decide to rebuild the engine rather than a complete re-power I would like locate one of these units. Are they a specific unit? Or are they simply just a newer mercruiser stern drive that will bolt in place of the orignal? When did mercruiser change their bolt pattern? I understand that a aplha will no bolt up to my current setup is that correct? Any info, part numbers or suppliers names would be greatly appreciated.

 

[ziggy]

Re: Retrofit Sterndrive for 1972 Mercruiser 120/140 I/O

if ya want a new drive. ya might check out the sei drives. i believe they're available right here on iboats store. ya could give sei a call too to be sure they're drive will work in your application..
i think you have an mc1 drive. a 1 drive
best i understand. a mc1, 1r, 1mr, or alpha1 gen. 1 will fit your application... a alpha1 gen. 2 will not fit. be sure to get the correct gear ratio for yer engine..

 

[72StarcraftChieftain]

Re: Retrofit Sterndrive for 1972 Mercruiser 120/140 I/O

wow, I didn't realize that I could swap stern drives that were that current. Of the four am I correct in assuming that the Alpha1 Gen1 would be the most desireable to use? Is there any one that would be the best or significantly cheaper to run than the others? Thanks for the info. This gives me a few more options and alittle more research to do.

 

[Bondo]

Re: Retrofit Sterndrive for 1972 Mercruiser 120/140 I/O

Of the four am I correct in assuming that the Alpha1 Gen1 would be the most desireable to use? Is there any one that would be the best or significantly cheaper to run than the others?

Ayuh,... Of the 4 noted by Ziggy,... The 1st 2 are virtually identical externally, but slightly different internally...
The latter 2 are virtually identical externally,+ different internally...
All 4 will mount,+ run on your transom assembley,... Provided you use the Short input shaft on whichever drive you use....

As also noted by Ziggy,... The SEI drives are pretty Cheap,.. Brand New....