Hi guys, I have just purchased an older P&D that was a race boat. According to the seller it has a 383 stroker paired to a ZF transmission to an SSM 3 (not sure if 3 or 3a)
I am new to this type of inboard scene and have been doing a lot of research. I see that mercury no longer carries most parts for these SSM 3, and my question is does it make sense to try rebuild or is it even possible? How many others are running this same set up?

I had 3's on my boat behind 600+ blown big blocks. I broke a prop shaft and was gearing up to rebuild the drives until I found a really nice pair to just bolt on. I was still gathering parts to build a spare pair of drives until I broke the hull, now I'm going to go a different direction. Good drives and used parts can still be found with some patience. I don't think you would ever hurt a 3 with a stroked small block but I'm not sure what maintenance parts are not available (bearings etc). it really depends on your budget.

3A's have a larger prop shaft than the 3's maybe 1.25 inch ? maintained correct they will last.............esp behind a mouse motor........

3As are keepers for sure.

There are still plenty of 3s around.

Is it possible to convert a ssm 3 to a 3a?......cost effective? or just not reasonable to do....just curious iis there no difference than propshaft & gears?

Thanks for the feedback, I have not taken possession of the boat yet so I really don't know what condition the drive is in.
She has been in storage for 2 years, and I am buying it sight unseen, so I was just curios as to what I might be up against.
Thanks again.

I've never needed a replacement part for my ssm3's, but I don't race my 35 cig nor run it hard....parts are not extinct, but to source them becomes harder as the years pass.
considering the boat your thinking about was raced, there's more than likely suspicion of worn internals....but a 383 pushing a ssm3 would be like a mac truck pulling a trailer
with a 18' donzi behind it......I run N/A 572's with my 3's and they fly & run & hold up well....remember heyday's 41' race Apache's ran ssm3's as well back then....you need to
know what condition they are in, but buying "sight unseen" is your roll of the dice......

The TRS prop shafts are pretty much a club as it is

The 3s with the double shaft system should never wear from power...just time in use.

The larger issue may be finding people that have the special tools and experience to rebuild them.
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TRS part of the drive has parts available...but getting harder and more expensive.

Any idea where I can find the 2 bow rails that I see on the Panteras?

3A is basically a longer #5 drive..
It`s a good, beefy, strong drive.
I sold a buddy a perfect pair and then he messed up and didn`t fill them properly, had air in the top and burned up the gears . Don`t do that . that`s an expensive party.