Hi guys I will like to know the difference between speedmaster 3,4and 5. thanks.

the 3 drive is a v bottom rive with a 750 hp max hp rating made for boats that need bow lift the 4 and 5 drives are short : and run at the surface and 750 hp max 18 i/n dia prop all requier a ext trammison

how much shorter are the #4 and 5 than the #3 drive.

can i run #5's on a deep v without standoff box and transom notch.

That will depend on where the X dim is set up.

Also, there are SSM3's and 3a's. The 3a's are stronger with (I think) larger propshafts.

Yup, 3A has a 26-spline large shaft, different internals as well.

If you want merc if not the 3 go for the 5 or 6

4's were only made for a short time around 1989.

They have not made 'plain 3's' in a long time. 3A's (which are basically a long version of a 5) and 5's are discontinued.

Barry

I was told the hp rating on #4's is 600hp

Cig 39, 4 or 5 has a prop shaft height 5.5" higher than a 3 or a 3A. I have run 850 hp thru small shaft fours and did fine. However, I am sure that if I had wanted to I could have went out and broken one by being stupid. New parts for the 3 and 4 are getting a little tough to find. 5 is ok. Seems like the gear selections are the first to dry up.