repower with outdrives

300DA

New Member
Jan 7, 2017
17
Anacortes
Boat Info
Its a 300 DA 1987.
Engines
1987 260'sx2. alpha's 1
I haven't been on here for a long time, but i need advice, I have to do a both engine and out drive replacement and was looking at these new engines for its replacement. I have a 87 SR Sundancer 300 DA with a pair of 5.7L 350 260hp along with Alpha's gen 2. This also came with the option of a pair of diesles. what type of engines and outdrives would any one suggest for the replacements.
Thanks.
 
for drives look at sei - much cheaper than factory alphas - for motors look at gm factory replacement "crate motors" or remans - michigan motorz can help you with all of the above...
 
what is sei? and was looking at motors there. been seeing they have the 5.7 MAG MPI complete 300hp would the alpha's gen ll handle this hp?
 
what is sei? and was looking at motors there. been seeing they have the 5.7 MAG MPI complete 300hp would the alpha's gen ll handle this hp?

Mercury told me to stick with a 5.0 for my 1987 alpha gen II. I asked about the 5.7 and they said it would be hard on the drive. My 5.0 MPI is 260hp.
 
Mercury told me to stick with a 5.0 for my 1987 alpha gen II. I asked about the 5.7 and they said it would be hard on the drive. My 5.0 MPI is 260hp.
Merc has always maintained that the Alpha drives were only good up to about 300 horsepower. However, there are instances where people have run higher HP motors with Alpha drives and not had a problem. I am one of those.

I have a 1985 cobalt CM23. The current motor is a GM 383 Stroker motor, generating about 350-375 HP, and an SEI 106 drive. I've never had a problem with the outdrive. I bought the boat with this package. On another forum I made a statement about my concern with having too much HP for my SEI drive. An SEI rep responded that they feel their drive could handle the HP. When asked if I could get that in writing he answered, "No". I worry about it but don't stress over it. But I don't abuse my boats. I don't jam the throttle to WOT. I don't run WOT but once in a while. I try to avoid jumping wakes or doing anything stupid that could stress the drive. Under these conditions I should be fine. That said, I wish I could justify the expense to switch to a Bravo drive. It is a 33-year old boat and I have sunk plenty into it.

In your case, a 350 Magnum is a 300 HP motor I believe and if that is the case an SEI drive should work for you. The SEI SE106 drive series are equivalent to the Alpha I and the SE 116 equals the Alpha II. I complete SE116 drive lists for $1595 and you can buy just the upper or lower case if that is al you need and everything mates to the Merc units.

I think Merc telling you that a 5.7 would be hard on the drive is just a case of CYA. There are literally thousands of 5.7/Alpha II packages out there. Remember, they have been building the Gen II drive since 1991. If you are not hard on your boat you should be fine with the 5.7/SE116 package. I hope things work out for you. That will be a big chunk of coinage for a 31-year old boat.
Shawn
 

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