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Upgrading from old Mercruiser 233 w Alpha 1 outdrive

M

moanytime

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"Great site. I have had the Se

"Great site. I have had the Sea Ray 24ft w/ hardtop for many years.Great boat and still in good shape.The Mercruiser 233hp(351) is raw water cooled.It was a new crate engine in 1985.I go 30 or 40 miles offshore.It has always ran well.It is time to good thru everything and I am worried alot about the internal corrosion.The boat is heavy and could use more power.I'm thinking...new engine,no carb, no points etc..What will work? Plug and play.Thanks beforehand."
 
"Well,.......

If you want t

"Well,.......

If you want to replace Just the motor,.....
Another 351 is your Only Option.......

Or,......
For $15,000. to 20,000.....
You can buy a Brand New Complete Driveline, Motor,+ Drive from Mercruiser....."
 
"Well....If I had that kinda $

"Well....If I had that kinda $$ I'd hang two E-Techs back there.On the other hand I could just buy another boat.I have been looking around for awhile.. Ebay, etc.. and sadly there aren't many 351's out there.There is a pair on Ebay right now that is close to me and sounds really good but they come w/ straight drive transmissions.Could this work w/ my bellhousing??Thanks."
 
"A 351 is a 351, the engine do

"A 351 is a 351, the engine doesn't know what's behind it for a bellhousing or transmission.
Yes, you can use MIE engines in a MCM application."
 
"mark;
351 options are limite

"mark;
351 options are limited as Merc only used this engine from 1973 to 1976, in 233 and 255 hp applications. The former used the model 1 drive, and the latter used the model II-TRS drive.
Yours is the 2 barrel carb version, right?
Rod"
 
"If it's an ALpha 1 drive

"If it's an ALpha 1 drive you can swap any engine in front of it up to about 300 hp; which is the recommended limit for the Alpha.

You could put a complete remanned bobtail 300 hp 5.7 l small block GM EFI in it.
These are on ebay for less than 6K complete. This comes complete with everything bolted on bellhousing forward, so pretty simple to swap in.

If you are thinking of much more than 300 hp you will need to also swap the drive for a Bravo.
Big bucks like bondo said.

Be aware that your increase in WOT speed will only equal the square root of the power increase; about 13 % going to 300 hp. Your normal cruise fuel consumption should not increase however, as the EFI is somewhat more efficient than a carbed engine.

Hope that helps,
Rod"
 
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