283 to 350 engine swap, questions

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workaholic

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Hi all!

I have a 1989 rinker bow rider that the previous owner took out the original motor and outdrive and installed a 1965-1967 283 (casting # 3862194). He also installed an old stringer outdrive. I was hoping to be able to just simply swap out the 283 for a pre-1985 350 rebuilt on eBay... Will this work?? Any modifications or changes that would need to be made??

Thanks in advance...
 
Bondo

Bondo

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Re: 283 to 350 engine swap, questions

Ayuh,.... It should be pretty much a straight up swap,...

only difference I can think of it the dipstick swapped sides of the block, 'bout 79...
 
W

workaholic

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Re: 283 to 350 engine swap, questions

thats what i am hoping for, just a straight up swap. I am not too familiar with car engines (im a small engine "mechanic"), thats why i am asking... I was getting a little worried while reading old posts about 283 to 350's and people having to swap a bunch or parts (ignition stuff, having to drill a hole in the crankshafts, etc etc) but I should not have to worry about any of that because I am not looking to use any of my 283 block (just the intake and exhaust manifolds, starter, etc etc), correct....

Thanks again
 
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workaholic

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Re: 283 to 350 engine swap, questions

another question i have is for the exhaust manifolds... On my 283 I have the old log style manifolds which run straight to the rear of the motor then elbow down to a rubber hose that joins it to the middle unit of the stern drive (stringer style outdrive).. Should I use the log style for the new 350 block??? or what style? is their a performance gain for either style?
 
Howard Sterndrive

Howard Sterndrive

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Re: 283 to 350 engine swap, questions

the 2 motors should be identical externally. Ignition should swap no issue.
might be a modest hp gain going to center riser manifolds over log style - I suspect 10HP maybe with a stock 5.7L... nothing you'd feel
 
Bondo

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Re: 283 to 350 engine swap, questions

Should I use the log style for the new 350 block??? or what style?
Click to expand...

Ayuh,... switchin' to center risers will be a problem, tryin' to plumb 'em into the exhaust ports on the drive...
'n there's really no performance gains in it anyways...
 
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workaholic

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Re: 283 to 350 engine swap, questions

now, how about running straight out the back of the log style manifolds thru the haul, bypassing the drive exhaust... Any idea on how to convert an old stringer outdrive to thru-haul exhaust?? Can i just simply re-route the 2 short rubber hoses (one per manifold) leaving the manifold and connecting to the ?middle? drive and just shoot them out the back, then cap off the inlets on the ?middle drive???
 
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workaholic

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Re: 283 to 350 engine swap, questions

sound.... I love the sound of a thru-haul exhaust.... is it as easy as that?
 
Howard Sterndrive

Howard Sterndrive

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Re: 283 to 350 engine swap, questions

oh, ok... yeah - it is that easy as long as you don't have selectrim (stringer units trim the drive by tipping the whole engine)
 
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stackz

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Re: 283 to 350 engine swap, questions

does that 283 run? if so, I wouldnt just junk it when you pull it. they are getting harder to find and people will pay money for a good running one, if the single barrel carb versions? makes me wonder if it has powerpack heads on it? look for a triangle on the lower sides of the heads.

people love using the 283 cranks in 327s to make z28 knockoff 302 engines...even though thats literally what gm did back in the day haha
 
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workaholic

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Re: 283 to 350 engine swap, questions

My stringer outdrive only has the electric tilt (motor located on the lower side of the outdrive)... The engine does not move...

My 283 has a new quadrajet 4 bbl carb installed on it... if that helps you out at all... The engine was running good all summer. then i started running Royal Purple in it and it seemed to have cleaned it out too much lol. Burning a bit of oil now and has some blow by...

As for the exhaust..... So my plan is to reroute the 2 hoses (1 per side) leaving the manifold and run them straight back through the hull... Then I will have to cap off the 2 inlets (one per side) in the middle drive.. correct?

Is there anything else i need to know about heights for the outlets in the hull? elbows, drops, etc ect...
 
Howard Sterndrive

Howard Sterndrive

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Re: 283 to 350 engine swap, questions

you might get some better through hull advice in the non repair section or via a search. Through hulls are illegal where I am, so I almost never see them. can't think if I've ever seen them behind a stringer.
 
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workaholic

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Re: 283 to 350 engine swap, questions

First off, thank you all again for all your help. Its all much appreciated!!! people like you(s) make other people much much much more knowledgeable!!

A new pre 1985 350 long block, including 4 barrel intake, torquer cam, hei ignition....
 
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