Thanks for the followup!
The Delco "15-63720" usually shows "Out of stock" or "NLA" on most websites for the past few years.
Amazon shows it in stock for $106, but "ships within 3-4 weeks" so that is suspicious to me.
"Professional, premium aftermarket replacement" -- that's also suspicious. My recent experiences on Amazon with the "AC Delco Store" shows they are either sending fakes or have switched all production to low quality offshore junk. I can handle offshore production, but there is no excuse for low quality with an OEM brand.
Curious to hear how well the Spectra/Carquest/Advance/Vista-Pro/Ready-Aire 398343 fits. Those are obviously made by one supplier and rebadged. Looking at the reviews, people are using this core on Fords. That doesn't give me great confidence. It may come close enough to fitting a Caprice. Be prepared for a fight. The dimensions aren't the same or close as below. Plus the inlet and outlet being both 0.625 which is wrong.
On the other hand, Part Number 398270 (Autozone) does seem like a better fit. I am dubious that 398343 is correct -- now that I see 398270.
More data points...
Just to show how much variation there is in size -- using the 2 NAPA ones that show up:
PN: RNR 1811452 (18-11453)
Brand REACH
Heater Core Thickness 1.25
Heater Core Width 6.06
Heater Core Length 8.38
Heater Core Inlet Size 1
Heater Core Outlet Size 0.625
PN: TEM 553778
Brand NAPA
Heater Core Thickness 1.375
Heater Core Width 6.5
Heater Core Length 8.25
Heater Core Inlet Size 0.625
Heater Core Outlet Size 0.75
PN: 398270
(found dimensions at
Northern Radiator, but this core is available as Spectra/Carquest/Advance/Vista-Pro/Ready-Aire)
Heater Core Thickness 1.25
Heater Core Width 6.06
Heater Core Length 8.375
Heater Core Inlet 0.75
Heater Core Outlet 0.625
PN: 398343 (I suspect this is wrong for a B-Body)
(Also from
Northern Radiator)
Heater Core Thickness 2
Heater Core Width 7.5
Heater Core Length 7.75
Heater Core Inlet 0.625
Heater Core Outlet 0.625
And the NOS Delphi (AC Delco OEM manufacturer) that I have in a box:
PN: Delphi HC0276 (I took these measurements myself)
Heater Core Thickness 1.3125
Heater Core Length 08.25
Heater Core Width 6.625
Heater Core Inlet Size 0.75
Heater Core Outlet Size 0.625
NOTES:
I normalized those measurements since the concept of length, width, height and thickness were all juxtaposed on the websites.
The Delphi one includes the cross bracket between the two pipes and the pipes are pre-clocked correctly.
The heater core dimensions are the core itself -- not counting the end tanks in the measurements (apparently).
The Delphi ones come with new foam. I remember the form factor being smaller than OEM and it needed new foam to prevent air bypass. I guarantee the old foam on the car is shot (disintegrated). I also guarantee that (due to these dimensional variations), you may want to have some HVAC/Weatherstripping sticky foam tape on hand. I'd say something like 3/4" wide by 3/4" thick roll on hand to cut to fill gaps.
I may still have an original stock OEM one in a scrap pile. When I do a scrap run in the spring/summer, and if I find it, I will take measurements of that one and update this post.