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I own a 1957 Chevy with a pre-1969 350 cid engine. the engine has a short water pump. I want to replace it with a long water pump. Is this an easy swap? Or do I have fitment concerns? Will it bolt right up, will the fan and pulley fit the LWP? Will there be sufficient radiator clearance? I want to do this to move the alternator to the passenger side of the engine. And help, info or suggestions are appreciated. Thanks.
 

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I own a 1957 Chevy with a pre-1969 350 cid engine. the engine has a short water pump. I want to replace it with a long water pump. Is this an easy swap? Or do I have fitment concerns? Will it bolt right up, will the fan and pulley fit the LWP? Will there be sufficient radiator clearance? I want to do this to move the alternator to the passenger side of the engine. And help, info or suggestions are appreciated. Thanks.

The long pump goes with the later heads that are machined on their ends for new mountings of engine driven accessories.


The long pump also requires a change to the crankshaft pulley to match the relocated position of the accessory pulleys.


Everything moves about 1-5/8ths inch forward of their current location.


The long pumps used 5/8ths and 3/4qtr shafts so you need to know your pump before ordering pulleys and fan.


Bogie
 

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More for Less Racer
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To add to what Bogie said...

The short and long water pump pulleys are different depth too, not interchangeable.

Power steering pump brackets are different, if the car has power steering.

Not sure on the space to clear the radiator....you may have to move the radiator to un front of the core support, in the original straight 6 radiator location.

Fan bot pattern should be the same, but make sure fan pilot fits tight to the pump shaft nose, don't use a fan with a 3/4" pilot on a 5/8" shaft pump. It will bolt on but not be centered by the tight fit to the shaft.
 

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Mark Goulette
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My question is why do you want to replace the short with the long? Functional wise, there is zero difference between the two. The long design was made to accommodate accessories found in later model vehicles since more things were added like power steering, a/c, and such....There is no advantage from one to another as far as cooling.

If it's for improved cooling, consider an aftermarket pump with a high efficiency impeller.
 

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Discussion Starter #5 (Edited by Moderator)
thank you for your responses. I am fairly new to the 350 engine. I have a '57 Chevy with a pre-1968 350 cid engine. The engine has a SWP. The alternator is located on the driver's side. I want to add power steering to the car. The power steering pump mounts to the driver's side of the engine. Therefore I am trying to move the alternator to the passenger side of the engine. The problem is that I cannot find an alternator bracket that works for my application and the SWP on the passenger side of the engine. I thought maybe installing a LWP might solve my problem. I can find an alternator bracket for the passenger side of the engine.

I know there is considerations regarding the crank pulley and clearance to the fan, etc. The LWP is closer to the radiator, etc.

Are you aware of any way I can accomplish putting the alternator on the passenger side of my engine? Do you know of a bracket that will work with little parts modification?

Please see photos. Thank you

350 engine (2).jpg

350 engine (4).jpg

350 engine (5).jpg
 

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It looks to me in that 1st pic that you have the mounting hole in the head for the alternator on the passenger side. Pre 69 SBCs didn't have that hole. I would find a 70s car with the whole setup along with PS pump in a junkyard and get everything you need. Pretty sure you wont have a rad clearance issue

 

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thank you for your responses. I am fairly new to the 350 engine. I have a '57 Chevy with a pre-1968 350 cid engine. The engine has a SWP. The alternator is located on the driver's side. I want to add power steering to the car. The power steering pump mounts to the driver's side of the engine. Therefore I am trying to move the alternator to the passenger side of the engine. The problem is that I cannot find an alternator bracket that works for my application and the SWP on the passenger side of the engine. I thought maybe installing a LWP might solve my problem. I can find an alternator bracket for the passenger side of the engine.

I know there is considerations regarding the crank pulley and clearance to the fan, etc. The LWP is closer to the radiator, etc.

Are you aware of any way I can accomplish putting the alternator on the passenger side of my engine? Do you know of a bracket that will work with little parts modification?

Please see photos. Thank you

View attachment 449287

View attachment 449289

View attachment 449291
The saw tooth mark identifies these as L31 Vortec heads which have the mounting features for accessories with a long pump if desired. But in addition to crank pulleys it needs the proper brackets

Check the block casting number to see if this isn't an L31 dressed to look more like the original 57 engine.

Bogie
 

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Just for the record depending on what you are seeking length wise, there is a 3rd Chevy water pump that exists that falls somewhere in between the long and short.
I had one in my 1967 GMC pickup.
 
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