97 OBS 5.7 Radiator

[RubnOneOut]

RockAuto has the Spectra Premium CU2317 which appears to be what you're looking for. Not sure why you didn't see it, comes right up for me when I select a '97 C1500 5.7L.

https://www.rockauto.com/en/moreinfo.php?pk=365701&cc=1031555&pt=2172



If you haven't already, grab the PDFs of the '97 GM factory service manuals from here. Way better than anything from Chilton or Haynes. The '97 manuals are on page 10, post number 92.

https://www.gmt400.com/threads/88-98-service-manuals.43575/page-10

I just grabbed the PDF, and thank you for those, it is much appreciated.

 

[df2x4]

Just noticed this... Be aware that the CU2317 I linked to has different sized transmission cooler line fittings than the CU624 that Caman96 posted according to the listings. The transmission cooler fittings on the CU2317 are 1/2"-20 UNF female and the CU624 has 5/8"-18 UNF female. Your lines may not fit the CU624 without modification.

 

[Caman96]

Won't the thickness of the core be an issue? I'm seeing it as 2-3/16

I don’t know if there’s a difference between C and K(mine), but it dropped right in for me like it was made to. Go to the Spectra site, add your truck and I’ll bet that’s one among others that are listed for it.

Just noticed this... Be aware that the CU2317 I linked to has different sized transmission cooler line fittings than the CU624 that Caman96 posted according to the listings. The transmission cooler fittings on the CU2317 are 1/2"-20 UNF female and the CU624 has 5/8"-18 UNF female. Your lines may not fit the CU624 without modification.

Now this may be a difference between C and K trucks. I’m going to check if the CU2317 is listed for mine. As always… verify, verify, verify!

 

[df2x4]

I don’t know if there’s a difference between C and K(mine), but it dropped right in for me like it was made to. Go to the Spectra site, add your truck and I’ll bet that’s one among others that are listed for it.

Now this may be a difference between C and K trucks. I’m going to check if the CU2317 is listed for mine. As always… verify, verify, verify!

I'm wondering if it's some weird difference between the trucks that got oil coolers factory and ones that didn't. I had to go check back in my 4L80E swap thread as I couldn't remember, but my red truck's ('97 C1500 4.3L) radiator has the 5/8"-18 transmission cooler fittings. It also has the engine oil cooler though...

 

[Caman96]

I just went and looked, the correct fittings were supplied with the CU624. I also went to Spectra site and it shows fitment for a 1997 C1500. Picture below showing CU624 installation and fittings provided.

You must be registered for see images attach

Also, you’ll want to immediately replace the little supplied rubber overflow cap with one of these silicone caps. The rubber will fail.
HPS 1" (25mm) Black High Temperature 3-ply Reinforced Silicone Coolant Cap Bypass Heater, 1-5/8" Length, 350F Max. Temp, 4mm Wall Thickness
https://a.co/d/4H78nYq

 

[df2x4]

So they're all probably 5/8"-18 and the CU624 just comes with adapters. Good to know!

 

[Caman96]

It’s also the perfect time to add a transmission cooler if you don’t have one.

You must be registered for see images attach

 

[RubnOneOut]

It’s also the perfect time to add a transmission cooler if you don’t have one.

You must be registered for see images attach

don't have the funds atm. Last shop visit hurt the wallet

 

[RubnOneOut]

I just went and looked, the correct fittings were supplied with the CU624. I also went to Spectra site and it shows fitment for a 1997 C1500. Picture below showing CU624 installation and fittings provided.

You must be registered for see images attach

Also, you’ll want to immediately replace the little supplied rubber overflow cap with one of these silicone caps. The rubber will fail.
HPS 1" (25mm) Black High Temperature 3-ply Reinforced Silicone Coolant Cap Bypass Heater, 1-5/8" Length, 350F Max. Temp, 4mm Wall Thickness
https://a.co/d/4H78nYq

 

[RubnOneOut]

Thank you for looking