engine swap ?

[jdcook]

I have a 1991 glassstream 21' oben bow ski boat.<br />It has a 4.3l v6 175 hp with a merc alpha one outdrive. I feel like this boat is underpowered and I want to put a 350 in it. I know someone who can put it in for me, so labor costs are not a problem. My question is what all do I need to get to do this and can some one tell me an approximate cost an all the parts that I would need.<br />Thank you for your info, any is appreciated.

 

[bluewater19]

Re: engine swap ?

All of the front tin should bolt right up to your 350. You will need to move your front mounts foward. new intake manifold, carb, hoses and all new exhaust manifolds, risers, y-pipe. Now you will need a new prop with all that power. might even need to put different gears in the outdrive.<br />It would be alot easier to find a complete drop-in bobtail. You might be able to get away with just a prop change depending on how powerful your new 350 is.<br />I was seriously thinking of doing the same thing in my boat. It came with a smallblock as an option. <br />I decided to just rebuild my 4.3 and hop it up a bit instead.<br />Good luck

 

[bluewater19]

Re: engine swap ?

Sorry forgot to say in other post.<br />You can get a drop in mercruiser 300hp mpi 350 mag motor for a little over $4,000 at www.govictorymarine.com <br /><br />This is a new motor with full mercruiser waranty.<br />I am in no way affiliated with these people. just found them when I was looking to do the same to my boat.<br /><br />They also have a mercruiser 4.3 mpi 220hp motor<br />that is plug and play for your boat for around $3,800. Call them up and ask for lane.<br /><br />Your 1991 175 hp 4.3 only puts about 155hp to the prop if it is a 2bbl.<br />Mercruiser rated the motors different in those days. So going from 155 at the prop to 220 would be a big jump. <br />It would also drop right in with very few mods.<br /><br />Just my 2 cents.

 

[jdcook]

Re: engine swap ?

bluewater,<br /><br />thanks for the info.<br />i was checking out some web pages and have found re-built 5.7ltr engines for 1200.00-1600.00 range. anyone everbouht an engine like this, just wondering. <br />Thanks, i am new to boating and any info would be helpful.

 

[Bondo]

Re: engine swap ?

jd,<br />A Recon engine would be Fine......<br />But, To do a Repower, You'll Need All the Bolt-on's...... The Easiest way is to buy a Donor motor/boat...<br />That way you'll Have all the nessessary Parts....<br />I will add, This is a Bigger Project than you Think......<br />You'll Also Have to Up-grade the Outdrive.......<br /><br />Just adding a 4bbl. carb. to the 4.3l, will give you Atleast 205hp...... More if you Trick it Out.....

 

[jdcook]

Re: engine swap ?

bondo,<br />when you say "up-grade" the outdrive what all do you mean? <br />are you saying get a new one or can i use the one i have, it is a alpha 1.

 

[Bondo]

Re: engine swap ?

You've got to Regear to a 1.50/1.........<br />From the 1.84/1 You've got Now........

 

[jdcook]

Re: engine swap ?

bondo,<br />thank you for the information