68 radiator hoses reference
Thread Starter
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Joined: Apr 2020
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68 radiator hoses reference
Hi,
I want to change the upper and lower hoses of the radiator cooling system. The GM references for my car are 3917670 and 3917671.
I want to buy it at Gates or Adelco. Does anyone have the exac corresponding references at Gates and Adelco ?
Do you have other good manufacturers for that in mind ?
Thank you.
Best regards.
I want to change the upper and lower hoses of the radiator cooling system. The GM references for my car are 3917670 and 3917671.
I want to buy it at Gates or Adelco. Does anyone have the exac corresponding references at Gates and Adelco ?
Do you have other good manufacturers for that in mind ?
Thank you.
Best regards.
Drifting
Joined: Jun 2025
Posts: 1,672
Likes: 582
If your old LOWER rad hose has a coil spring fitted inside it: do Keep that spring as you may need to reuse it !
Some new LOWER rad hoses have the spring; while others do Not. Some hoses' construction is stiff enough to prevent this; while others are puny.
That spring can help prevent the pump from sucking the hose closed (akin to a surgical cardiovascular stent); preventing overheating.
Some new LOWER rad hoses have the spring; while others do Not. Some hoses' construction is stiff enough to prevent this; while others are puny.
That spring can help prevent the pump from sucking the hose closed (akin to a surgical cardiovascular stent); preventing overheating.
Race Director
Joined: Mar 2016
Posts: 14,325
Likes: 8,129
From: Napa Valley California
The reproduction hoses from Dr Rebuild, Bairs, Corvette Central, and Top Flight Automotive are all Gates hoses.
Not the cheap ones but the pricier ones.
The lower hose I just purchased came with the new spring already installed, just make sure it states it’s included.
They have the oem numbers stamped on them and don’t say they are Gates hoses, but they are.
Don’t buy the cheap ones they aren’t Gates hoses.
Not the cheap ones but the pricier ones.
The lower hose I just purchased came with the new spring already installed, just make sure it states it’s included.
They have the oem numbers stamped on them and don’t say they are Gates hoses, but they are.
Don’t buy the cheap ones they aren’t Gates hoses.
Thread Starter
Advanced
Joined: Apr 2020
Posts: 89
Likes: 1
If your old LOWER rad hose has a coil spring fitted inside it: do Keep that spring as you may need to reuse it !
Some new LOWER rad hoses have the spring; while others do Not. Some hoses' construction is stiff enough to prevent this; while others are puny.
That spring can help prevent the pump from sucking the hose closed (akin to a surgical cardiovascular stent); preventing overheating.
Some new LOWER rad hoses have the spring; while others do Not. Some hoses' construction is stiff enough to prevent this; while others are puny.
That spring can help prevent the pump from sucking the hose closed (akin to a surgical cardiovascular stent); preventing overheating.
Thank you.
Thread Starter
Advanced
Joined: Apr 2020
Posts: 89
Likes: 1
The reproduction hoses from Dr Rebuild, Bairs, Corvette Central, and Top Flight Automotive are all Gates hoses.
Not the cheap ones but the pricier ones.
The lower hose I just purchased came with the new spring already installed, just make sure it states it’s included.
They have the oem numbers stamped on them and don’t say they are Gates hoses, but they are.
Don’t buy the cheap ones they aren’t Gates hoses.
Not the cheap ones but the pricier ones.
The lower hose I just purchased came with the new spring already installed, just make sure it states it’s included.
They have the oem numbers stamped on them and don’t say they are Gates hoses, but they are.
Don’t buy the cheap ones they aren’t Gates hoses.
Race Director
Joined: Mar 2016
Posts: 14,325
Likes: 8,129
From: Napa Valley California
For our Corvettes, I would stick with one of the Corvette parts vendors I referenced which are all commonly used by forum members.
You can also add Zip Corvette into the list.
Some vendors will provide the GM part numbers in the items posted on their web page for the part, others may not.
The good reproduction hoses usually have the GM part numbers printed on the hose but won’t say “Gates” because the original factory hoses may not have had the Gates logo printed on the hose.
Pay close attention to year model, engine model, and under hood accessories when ordering new hoses.
The upper and especially lower hoses can be very different even between two Corvettes of the same year with 350 cu in engines.
For example your radiator outlet may be 1 3/4” but your thermostat housing may be 1 1/2”.
The spring in the lower hose is there to keep the hose from collapsing under pressure.
Even it your current hose doesn’t have one, it is needed and the hose could have been replaced by a prior owner and the incorrect hose might have been installed.
You can also add Zip Corvette into the list.
Some vendors will provide the GM part numbers in the items posted on their web page for the part, others may not.
The good reproduction hoses usually have the GM part numbers printed on the hose but won’t say “Gates” because the original factory hoses may not have had the Gates logo printed on the hose.
Pay close attention to year model, engine model, and under hood accessories when ordering new hoses.
The upper and especially lower hoses can be very different even between two Corvettes of the same year with 350 cu in engines.
For example your radiator outlet may be 1 3/4” but your thermostat housing may be 1 1/2”.
The spring in the lower hose is there to keep the hose from collapsing under pressure.
Even it your current hose doesn’t have one, it is needed and the hose could have been replaced by a prior owner and the incorrect hose might have been installed.
Drifting
Joined: Jun 2025
Posts: 1,672
Likes: 582
If your old LOWER rad hose has a coil spring fitted inside it: do Keep that spring as you may need to reuse it !
Some new LOWER rad hoses have the spring; while others do Not. Some hoses' construction is stiff enough to prevent this; while others are puny.
That spring can help prevent the pump from sucking the hose closed (akin to a surgical cardiovascular stent); preventing overheating.
Some new LOWER rad hoses have the spring; while others do Not. Some hoses' construction is stiff enough to prevent this; while others are puny.
That spring can help prevent the pump from sucking the hose closed (akin to a surgical cardiovascular stent); preventing overheating.
It's not just vettes, or just GM, lotsa cars have a spring in lower hose.
I learned that long ago; when I also learned to not discard the spring.
Most chevy of the era have smaller 1-1/2" ID hose at top and larger 1-3/4" ID hose at bottom.
Chevy's of the C4 era usually have same smaller 1-1/2" ID hose at top BUT Some have a different 1-5/8" ID lower hose (still larger than at top).
Most systems of the era feed the pump with a Larger ID lower hose than outlet's upper hose ID.
Hence. C3 lower hose isn't under positive pressure, pump is pulling a negative pressure. Pump pulls hard enough to collapse lower hose (ergo spring); can also pull hard enough to cause coolant to cavitate near pump's lower inlet (lower pressure also lowers boiling point).
OTOH, pump is pushing a positive pressure thru the block, heads and out of intake manifold to top of rad's inlet
There Is a pressure differential across system. As the very hot coolant leaves motor and enters top of rad, it begins to drop temp And its pressure also begins to drop.
