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Chevy 350 Block Differences

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Old 06-25-2020, 02:53 PM
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Default Chevy 350 Block Differences

I'm sort of new to chevy 350s and I have a lot of them in the shop right now and im looking for some clarification on mainly dip stick location of the different blocks. The current boat I'm working on is a 1981 sea ray that I pulled what I thought was an early generation block (pre-vortec?) With a 2 piece main seal, the dip stick on the same side as the starter, and heads with the valve cover bolts on the outside. The motor I have to replace it is the exact same, except the dip stick is on the same side as the oil filter, and unfortunately is not threaded to suck the oil out.

I have a 1980 Chris Craft Scorpion with twin 350s and both those motors have the dip stick on the same side as the oil filter and valve cover bolts on the outside of the head.

Now I also have a 1997 Maxum in the shop that I'm replacing the motor on and that has a 1 piece rear main, the dip stick on the same side as the starter, and heads that have the valve cover bolts in the middle.

My 1986 Power Play 230 Conquest has the dipstick on the same side as the starter, and valve cover bolts on the outside of the head.

Am I correct in thinking I have 3 different styles of blocks?
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Old 06-25-2020, 06:01 PM
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Originally Posted by Ryanw10
I'm sort of new to chevy 350s and I have a lot of them in the shop right now and im looking for some clarification on mainly dip stick location of the different blocks. The current boat I'm working on is a 1981 sea ray that I pulled what I thought was an early generation block (pre-vortec?) With a 2 piece main seal, the dip stick on the same side as the starter, and heads with the valve cover bolts on the outside. The motor I have to replace it is the exact same, except the dip stick is on the same side as the oil filter, and unfortunately is not threaded to suck the oil out.

I have a 1980 Chris Craft Scorpion with twin 350s and both those motors have the dip stick on the same side as the oil filter and valve cover bolts on the outside of the head.

Now I also have a 1997 Maxum in the shop that I'm replacing the motor on and that has a 1 piece rear main, the dip stick on the same side as the starter, and heads that have the valve cover bolts in the middle.

My 1986 Power Play 230 Conquest has the dipstick on the same side as the starter, and valve cover bolts on the outside of the head.

Am I correct in thinking I have 3 different styles of blocks?
Yes you are correct, 3 different blocks you have
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Old 06-26-2020, 05:32 AM
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Originally Posted by oconnor marine
Yes you are correct, 3 different blocks you have
Thank you. So I'm weighing out my options on what to do for the dip stick on the motor I have going back into the sea ray. Currently it's got some sort of fabricated pan with a drain plug and an automotive style dipstick tube. This was a customer supplied motor and I'm having a hard time locating the correct marine style dipstick tube. I'm thinking either I tell the customer to find an oil extractor that fits all the way down the dipstick tube, or I rig up some a/n lines and fittings to the drain plug in the pan. Anyone have other thoughts or feedback?
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Old 06-26-2020, 06:06 AM
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Originally Posted by Ryanw10
Thank you. So I'm weighing out my options on what to do for the dip stick on the motor I have going back into the sea ray. Currently it's got some sort of fabricated pan with a drain plug and an automotive style dipstick tube. This was a customer supplied motor and I'm having a hard time locating the correct marine style dipstick tube. I'm thinking either I tell the customer to find an oil extractor that fits all the way down the dipstick tube, or I rig up some a/n lines and fittings to the drain plug in the pan. Anyone have other thoughts or feedback?
i have an 12v oil sucker mounted to a 2.5 gal bucket has clamps to attach to battery. 4 foot Rigid plastic tube slides all the way down tube to bottom of pan. Works mint . Any dipstick.

have one like this for over 15 years.

Last edited by oconnor marine; 06-26-2020 at 06:09 AM.
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Old 06-28-2020, 09:48 AM
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This was a customer supplied motor and I'm having a hard time locating the correct marine style dipstick tube. I'm thinking either I tell the customer to find an oil extractor that fits all the way down the dipstick tube,
Ayuh,.... This is correct,.... forgetabout the "Or" part,....
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Old 06-29-2020, 12:05 PM
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Thanks for the help guys. The motor is back in the sea ray now and its time to get it buttoned back up so I can get back to working on my power play!
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Old 07-02-2020, 09:57 AM
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So I just got the block and heads back from the machine shop for the 1997 maxum I talked about in the first post and started assembling this morning. The cam shaft that was in it had some rust and I do not want to use it. Now I have a cam shaft from a 90s truck that is good, as well as the cam from the 1981 sea ray cracked block motor that I disassembled. Both are clean and good and I would like to use the one from the sea ray. Are the cams the same from the 80s motor to the 90s motor?

Edit:
I will also add the marine cam from the 80s motor still has rough cast material between lobes and bearing surfaces, the 90s marine cam has a machined finish through out the cam.

Last edited by Ryanw10; 07-02-2020 at 10:00 AM.
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Old 07-02-2020, 10:50 AM
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The maxum has a vortec motor with roller cam no? If so needs to be roller cam
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Old 07-02-2020, 10:57 AM
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Originally Posted by Ratty206ls
The maxum has a vortec motor with roller cam no? If so needs to be roller cam

Yep, I'm an idiot. Been a while since I disassembled this motor and for whatever reason was thinking it was flat tappet. So with that being said should I see if the machine shop can polish my vortec marine cam or would the truck cam be acceptable?
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Old 07-02-2020, 11:18 AM
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Sorry I wasn’t implying you were and I might have been thinking to much about all the motors you mentioned in the original post with perimeter style valve cover non vortec. I consider it to be a step back putting a flat tappet into something original roller for obvious service life. The truck most likely had a cam for low end torque like a boat needs
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