1987 GM 305 x 2 rebuild questions.

Alumarine

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the drive are OMC and look to be in good condition on the exterior zero scuff but will get to that once engine are ready.
Just a heads up that OMC drives can be difficult to find parts for and mechanics that can service them.
 

Scott Danforth

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Sei does an OMC drive conversion to one of there mercruiser clones
 

acadian2022

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Just a heads up that OMC drives can be difficult to find parts for and mechanics that can service the

Just a heads up that OMC drives can be difficult to find parts for and mechanics that can service them.
Good day, I found a few places that carry most parts I'm fortunate some of my family member here have machine shop and are machinist if its made of metals they pretty much can reproduce anything. shaft, gears etc. thank you for the heads up.
 

acadian2022

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and even the later LS and LT motors. the GM chevy bolt pattern will also bolt up Big Blocks, in-line 4's and 6's, etc.
Ok thank you. I may have found 4 options two SBC 350 or 2 SBC 305 still in the trucks and runners I'm waiting for serial numbers to research them a big thank you again for all your assistance.
 

briangcc

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I'd want the down low grunt of the 350 over the 305. The old saying is true...there's no replacement for displacement.
 

Scott Danforth

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Ok thank you. I may have found 4 options two SBC 350 or 2 SBC 305 still in the trucks and runners I'm waiting for serial numbers to research them a big thank you again for all your assistance.
I would go 350's.

make sure the two trucks are the same vintage from a motor point of view . preferably 1996-2000 (vin code R). this will be vortec heads (8 intake bolts)

however the prior vintage is 1990-1995 (vin code K). this will be non-vortec heads (12 intake bolts)

or 1988-1989 (vin code K or M). still non-vortec, however minor changes in the motor for 1988/89

or 1987 (vin code M).

if 1986, you have to verify the block casting numbers

No 1985 or older
 

acadian2022

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Good day all. Moving forward with 350 2 bolt main rear single seal. I've got one a runner however I want them as new as they get so full tear down and at the machine shop for cleaning inspection and then looking for another one. The one I got was free from my cousin was inside great shape.
 

Scott Danforth

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Good day all. Moving forward with 350 2 bolt main rear single seal. I've got one a runner however I want them as new as they get so full tear down and at the machine shop for cleaning inspection and then looking for another one. The one I got was free from my cousin was inside great shape.
what vintage?
 

acadian2022

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what vintage?
Good day all. they are both 1995 vortex 350 mechanical fuel pump. now Ive spent lots of time online to read up on twin engine setup and I have yet figured out rotation of twin engine boat out from the boat manufacture for my model if my boat engine rotation was both clockwise or counter clockwise I sent email this am to Bayliner asking the question. I have no issue to purchase proper crankshaft / cam etc to have one engine LH one RH if that's the smart way to go about it. I have all the parts of the 305 that was in the boat and will compare crankshaft and cams today if they look the same or not mind you previous boat owners may have changed engine in this boat in the pass? again a huge thank you for all the help.... Oh casting number for the two 350 is 10243880 heads are 14102193 I was informed that my 305 intake will fit and I tried the flywheel and flange and they fit perfectly. most likely will buy 2 new intake do.
 
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Scott Danforth

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Good day all. they are both 1995 vortex 350 mechanical fuel pump. now Ive spent lots of time online to read up on twin engine setup and I have yet figured out rotation of twin engine boat out from the boat manufacture for my mode
verify before you worry. both should be LH. however pull the timing covers on your old 305's if you have chains on both, they are LH. if one has a gearset, its a RHmotor
 

Bondo

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verify before you worry. both should be LH. however pull the timing covers on your old 305's if you have chains on both, they are LH. if one has a gearset, its a RHmotor
Ayuh,..... The odds are slim to none that you have a right-handed motor,.....
Reverse rotation is accomplished in the drive/ transmission since the early '70s,....
 

acadian2022

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verify before you worry. both should be LH. however pull the timing covers on your old 305's if you have chains on both, they are LH. if one has a gearset, its a RHmotor
Hi Scott. both 305 had timing chain. one 305 had a double timing chain gear was 2 different 305 in that boat from the beginning that could explain that right? one from the casting number was saying truck 305 and the other casting said passenger 305 like Monte Carlo thank you Scott
 

acadian2022

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Hi Scott. both 305 had timing chain. one 305 had a double timing chain gear was 2 different 305 in that boat from the beginning that could explain that right? one from the casting number was saying truck 305 and the other casting said passenger 305 like Monte Carlo thank you Scott
To clarify one crankshaft had 2 gears I could post pictures tomorrow of the 305 crankshaft if that helps?
 

Scott Danforth

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If you have a gear set. Not a timing chain set. However two gears. Only then do you have a RH motor.

However 99.9995% sure you have 2 LH motors
 

acadian2022

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If you have a gear set. Not a timing chain set. However two gears. Only then do you have a RH motor.

However 99.9995% sure you have 2 LH motors
the two 305 100% was running on timing chain its just when I went and checked the shaft yesterday notice on crankshaft had 2 gears assuming that would have been for a double timing chain set up. I have one 350 ready for the machine shop just to clean the blocks and heads and possibly a light cross hatch since I will be change all the piston rings to attempt to have the engine run as new as possible once they are re installed in the boat since its a big job vs re installing engines in vehicles so much more accessible vs a boat that's for sure. I also order that special shaft to align the engine properly with steerdrive. All I think about these days is this boat :). again to you Scott and all that jumps in to help is amazing and if one day I head-up your way dinners on me....
 

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acadian2022

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Good day all. Do anyone know if I could use the balancers from the 305 for the 350 block? Reason I'm asking only one of the two 350 had a balancer and the 350 balancer is bigger then the one from the 305. Thank you all. If so wanted to keep the shaft and crankshaft with the 350 engine and use the 305 balancer if that's ok?
 

Scott Danforth

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as long as the balancer is good, they are internal balanced engines. If it was me, I would spend $45 on new balancer
 
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