swapping engines from Ford 302/mercruiser to 350 OMC

74 reinell

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Jun 23, 2009
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I was wondering if anybody has done this swap and if anyone knows what I will need to do so. I want to keep the mercruiser outdrive and use the chevy 350 engine. Looking for more power. Do I need to change out the bell housing. Hopefully someone has some good tips. Thank you.
 

Haut Medoc

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Re: swapping engines from Ford 302/mercruiser to 350 OMC

Not worth the effort unless you want to do a complete repower, you will drain your bank account in the attempt....;)
Welcome to iboats, btw....:)
 

Bt Doctur

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Re: swapping engines from Ford 302/mercruiser to 350 OMC

Engine
fab new front mounts
change engine rear cover, if 12 going to a 9 ,change inner transom plate
change exaust "Y" pipe
change manifolds and risers
TOTAL=????????????
 

74 reinell

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Re: swapping engines from Ford 302/mercruiser to 350 OMC

My boat is a 74 and I have a complete 78 reinell with all the parts engine, outdrive everything. Do you still think it is not worth the time and money or should I change props or build up the 302 that I have. Is there a more compatable swap. Thank you for all your help.:)
 

Haut Medoc

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10,645
Re: swapping engines from Ford 302/mercruiser to 350 OMC

What is the rated HP of the present engine?...
It should be right there on the valve cover......
None of your OMC parts will work, other than a complete repower....
An OMC that old is a stringer drive, forget it.....
Part out the OMC stuff & get either a new 302 with a 4bbl or go up to a 351.....;)
 

74 reinell

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Re: swapping engines from Ford 302/mercruiser to 350 OMC

I will check for the horse power rating tonite. Will the 351 fit in the 302s place without to many problems. Or is the 4bbl the way to go. The 302 runs really good I just would like to have a little more snoot for going over the bar and such. You know what I mean. I thought I would do the 350 swap because I have the parts and I know that engine runs very strong. I really appriciate your help.
 

Haut Medoc

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10,645
Re: swapping engines from Ford 302/mercruiser to 350 OMC

I will check for the horse power rating tonite. Will the 351 fit in the 302s place without to many problems. Or is the 4bbl the way to go. The 302 runs really good I just would like to have a little more snoot for going over the bar and such. You know what I mean. I thought I would do the 350 swap because I have the parts and I know that engine runs very strong. I really appriciate your help.
A 4bbl will get you up to about 215 hp or so, but a 4bbl cast manifold is very rare to find.....
If you have closed cooling, you could go with an after market one....
A 351 from ebasicpower will get you up to 285 hp....
The most significant modification to go to the 351 will be the intake manifold, & the y pipe as the 351 is a little taller & wider than a 302....
You could skirt the y pipe issue if you go to center rise manifolds & risers....;)
 

gadget73

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Jun 20, 2009
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Re: swapping engines from Ford 302/mercruiser to 350 OMC

351 is mostly interchangable with a 302. Same bellhouse, same exhaust manifolds, same engine mounts and spacing, and for the most part the engine accessories will not be a problem unless they mount up to certain holes in the head and to the water pump. Different intake manifold, distributor and oil pan though. One thing to be aware of on a 351, it has a taller deck height. What this means in practical terms, is not only is it taller, its wider. This might be a problem with your exhaust and maybe with other items in your engine bay. Its not a great deal bigger, but if your bay is really really tight, you'll want to be aware of it.
 

74 reinell

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Re: swapping engines from Ford 302/mercruiser to 350 OMC

I will check the horse power tonight. It sounds like maybe the 351 would be the way to go then huh? What is ebasicpower, a company or what are you talking about? Also are the center rise manifolds and risers available that you know of?
 

74 reinell

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Re: swapping engines from Ford 302/mercruiser to 350 OMC

Can I use a 351 cleveland out of a ford truck or is the rotation wrong. I realize I would have to put all the marine stuff on it but will the long block work?
 

maxxman04

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Mar 30, 2009
Messages
352
Re: swapping engines from Ford 302/mercruiser to 350 OMC

a bigger cam, better ignition system, i.e. new points, good plug, low resistance wires, can yield quite a power gain out of the 302, without costing an arm and a leg.
 
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