As many others have over the years, I have searched for a higher capacity radiator for the post 2003 Chevies many times without success.
As it turns out, there does appear to be a radiator that seems to fit the requirements and is nearly a drop in.
The actual application is for the previous generation Express van and before they switched to the 8.1 liter gas engine and still had the 7.4 liter. I think we never found it before, as we all were looking at small block stuff, and in those years the 5.7L radiator was 3" narrower than the current version. Odd part is that they used the width radiator as the new ones have for the diesel and the 7.4L. I used model year 1998 which is in the middle of the years.
It also appears that they carried over a lot of parts, and/or dimensions at the generation change in 2003. The mounting system (saddle) and shroud setup are nearly identical), and you could even put the old narrower 5.7 radiator in a newer Chevy, it appears, as well as the wider one, with just a shroud change and some baffles. The important part is that the saddle and top shroud (which holds the top saddle isolaters are sill sized to handle the two core radiator from the diesels and 7.4L engines, as well as the single core stock radiators we all have.
The differences between a stock 1 1/16" core radiator and the two core 2.125" core radiator are pretty easily handled, IMO. Of interest is that the two core also has tighter fin spacing at 7 fins/inch compared to 6 fins/inch for the stock radiator.
The lower radiator hose is the same diameter, but the new ones have a quick connect to the radiator and the older one is a normal hose barb connection.
The vent hose that goes into the radiator right below the radiator cap is not on the older style radiator, but they have a heater hose sized connection just a bit lower, so the size of the hose needs to be adapted.
The radiator cap is the two ear type that has been used for decades instead of the threaded cap on the newer radiators. Both use a non pressurized overflow tank which is a surprise because a lot of the 90s GM stuff used the pressurized overflow.
That is it for the differences that need to be handled to get twice as much core area as the stock radiator has. Of course, stacked cores like this are not as efficient as two single cores, but most would say they get over 50% more capacity out of them.
I personally have two aftermarket units of the old style radiators, and one looks like it would fit as above, and was just purchased from Spectra. The other was from a local junk yard that I got to see if it all would actually work out. It has a squarer tank on the driver side, so required a slight change to plastic core support. I don't think the Spectra would require it, but don't know for certain because I had already done the change to the core when I got it.
Here are the OEM and the Spectra side by side
The difference in the outlets
The different vent tube connections and radiator cap area
Here are the lower radiator saddle mount isolators I took out. The radiator just sits on them at the crimp between the core and the tanks. These were identical at one time, so obviously, the oil spilled from my several cooler experiments attacked them. One has grown over 3/8" from the oil and gotten very soft and sticky. It is nearly impossible to disconnect the coolers without the isolaters getting oily, so best to just buy two for the bottom, the tops survive fine and can be reused.
As it turns out, there does appear to be a radiator that seems to fit the requirements and is nearly a drop in.
The actual application is for the previous generation Express van and before they switched to the 8.1 liter gas engine and still had the 7.4 liter. I think we never found it before, as we all were looking at small block stuff, and in those years the 5.7L radiator was 3" narrower than the current version. Odd part is that they used the width radiator as the new ones have for the diesel and the 7.4L. I used model year 1998 which is in the middle of the years.
It also appears that they carried over a lot of parts, and/or dimensions at the generation change in 2003. The mounting system (saddle) and shroud setup are nearly identical), and you could even put the old narrower 5.7 radiator in a newer Chevy, it appears, as well as the wider one, with just a shroud change and some baffles. The important part is that the saddle and top shroud (which holds the top saddle isolaters are sill sized to handle the two core radiator from the diesels and 7.4L engines, as well as the single core stock radiators we all have.
The differences between a stock 1 1/16" core radiator and the two core 2.125" core radiator are pretty easily handled, IMO. Of interest is that the two core also has tighter fin spacing at 7 fins/inch compared to 6 fins/inch for the stock radiator.
The lower radiator hose is the same diameter, but the new ones have a quick connect to the radiator and the older one is a normal hose barb connection.
The vent hose that goes into the radiator right below the radiator cap is not on the older style radiator, but they have a heater hose sized connection just a bit lower, so the size of the hose needs to be adapted.
The radiator cap is the two ear type that has been used for decades instead of the threaded cap on the newer radiators. Both use a non pressurized overflow tank which is a surprise because a lot of the 90s GM stuff used the pressurized overflow.
That is it for the differences that need to be handled to get twice as much core area as the stock radiator has. Of course, stacked cores like this are not as efficient as two single cores, but most would say they get over 50% more capacity out of them.
I personally have two aftermarket units of the old style radiators, and one looks like it would fit as above, and was just purchased from Spectra. The other was from a local junk yard that I got to see if it all would actually work out. It has a squarer tank on the driver side, so required a slight change to plastic core support. I don't think the Spectra would require it, but don't know for certain because I had already done the change to the core when I got it.
Here are the OEM and the Spectra side by side
The difference in the outlets
The different vent tube connections and radiator cap area
Here are the lower radiator saddle mount isolators I took out. The radiator just sits on them at the crimp between the core and the tanks. These were identical at one time, so obviously, the oil spilled from my several cooler experiments attacked them. One has grown over 3/8" from the oil and gotten very soft and sticky. It is nearly impossible to disconnect the coolers without the isolaters getting oily, so best to just buy two for the bottom, the tops survive fine and can be reused.
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