Notices
1973 - 1979 F-100 & Larger F-Series Trucks Discuss the Dentsides Ford Truck
Sponsored by:
Sponsored by: Moser

1973 Heater Core Question

Thread Tools
 
Search this Thread
 
Old Feb 9, 2010 | 09:25 PM
  #1  
AlaskanCummins's Avatar
AlaskanCummins
Thread Starter
|
New User
Joined: Jul 2008
Posts: 19
Likes: 0
From: Alaska
1973 Heater Core Question

I know this has been hashed out as I've read all of the past posts reguarding the high output heater core that was available in 1977.5-1979 Ford trucks.

Now, this is what I have in my possession: Heater core with part number on it and the box as D3TZ18476A. There is a past post that states that this core is the ECONOMY type, but alas it isn't. The unit I have measures 8x6x2; the high output core.

I went to the FoMoCo part number decoder page. This number decodes as this: D - the 1970's; 3 - last digit of year of introduction or revision; T - truck and Z - Ford service parts.

Now, the question I have is this: If in fact the number 3 states that this part was INTRODUCED or was revised in 1973, that would mean that this existed PRIOR to the high output heater option of the late 70's.

Unfortunately, the only date on the box is October 18th. No year; except for a small '75 in the lower left corner.

Did I read/decode this part number correctly?

By the way, I have a 1973 F-250 4x4 with factory AC.
 
Reply
Old Feb 10, 2010 | 01:15 AM
  #2  
montana_highboy's Avatar
montana_highboy
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Originally Posted by AlaskanCummins
Now, the question I have is this: If in fact the number 3 states that this part was INTRODUCED or was revised in 1973, that would mean that this existed PRIOR to the high output heater option of the late 70's.
Your assumption is correct the Hi-output heater was available prior to 78/79, it came on trucks equipped with the "Northlander" package and was standard on most if not all crew cabs and supercabs (more cubic feet to heat).
 
Reply
Old Feb 10, 2010 | 03:58 PM
  #3  
AlaskanCummins's Avatar
AlaskanCummins
Thread Starter
|
New User
Joined: Jul 2008
Posts: 19
Likes: 0
From: Alaska
Thanks Montana - this is interesting. My truck was originally sold in Colorado Springs, CO and I wonder if it has this "northlander" package. It's only a standard cab though.

I do have the build sheet that I found under the seat. Do you know how to decipher that?
 
Reply
Old Feb 10, 2010 | 04:18 PM
  #4  
montana_highboy's Avatar
montana_highboy
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
I know the Northlander package came with dual batteries, engine block heater and hi-output heater, what other features it might have had i'm not sure.
 
Reply
Old Feb 10, 2010 | 04:44 PM
  #5  
starmilt's Avatar
starmilt
Post Fiend
Joined: Oct 2007
Posts: 10,501
Likes: 5
From: Faibanks Ak.
My 76 has the high out put heater and I bought it in texas, there is no air and it never had dual batteries, so it must have come in some that didn,t have the whole northland package.
 
Reply
Old Feb 10, 2010 | 05:46 PM
  #6  
AlaskanCummins's Avatar
AlaskanCummins
Thread Starter
|
New User
Joined: Jul 2008
Posts: 19
Likes: 0
From: Alaska
Mine had a 360, block heater and only one battery.

What I'm having is this darn low temperature air from the heater problem. Fan blows real nice and I've already checked ductwork, etc. I flushed it out yesterday. Hoses hot on both in/out - in is hotter than out is too; but both are hot.

Running 195* T-stat, hood blanket, grille cover and electric fans set to off. I believe the truck is coming up to temp as the guage is about 1/3 to half in normal.

I just don't want to tear it apart to find that it may have the larger core in it already with me just expecting too much out of it. The truck is 36 years old ya know!

I'm afraid that I may be victim of someone else putting in the smaller core when it had the larger one in it, leaving that 2" gap.
 
Reply
Old Feb 10, 2010 | 06:11 PM
  #7  
montana_highboy's Avatar
montana_highboy
Post Fiend
Joined: Apr 2008
Posts: 8,261
Likes: 15
From: Big Sky Country
Originally Posted by AlaskanCummins
Running 195* T-stat, hood blanket, grille cover and electric fans set to off.
With all those measures taken you should have ample heat, my heater is only the economy core (6x6x2) and it virtually roasts me out of the cab even on low.
 
Reply
Old Feb 10, 2010 | 06:24 PM
  #8  
starmilt's Avatar
starmilt
Post Fiend
Joined: Oct 2007
Posts: 10,501
Likes: 5
From: Faibanks Ak.
Something is not right it should roast you out even at alaska temps, but air takes the path of least resistance so if it can get around it it will. Where you at in ak.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-1

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-2

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-3

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-4

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-5

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-6

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-7

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-8

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-9

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
Old Feb 10, 2010 | 07:35 PM
  #9  
mikeo0o0o0's Avatar
mikeo0o0o0
Hotshot
15 Year Member
Liked
Loved
Community Favorite
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
Club FTE Gold Member
D3TZ-18476-A Core Assy., Heater Fits 73-up F100-350 w/ integral A/C or Hi-low vent system.
C6OZ-18476-B Core Assy., Heater fits 73-up w/ High output (8" core)
 
Reply
Old Feb 10, 2010 | 07:51 PM
  #10  
AlaskanCummins's Avatar
AlaskanCummins
Thread Starter
|
New User
Joined: Jul 2008
Posts: 19
Likes: 0
From: Alaska
I'm in Eagle River; basically south-central just north of Anchorage.

Ambient temperature today is 28*F. Took truck out twice today and got her all warmed up. First time, the heat was like before - just kinda luke warm. Second time, it was noticably warmer, basically like I think it should be. I don't know why it got warmer on the second go around.

So Mike, if I'm reading this correctly, my truck should have the "high output" core in it already, since the one I have in my grubby hands is the D3TZ part # and it measures 8x6x2.

I have an idea: I suppose if I could get all the coolant out of the core, measured it and put it back in and see if it's the same amount that the core I have on my bench takes. That way, I'd know what size core's in my truck before I go ripp'n stuff out.

Thanks for the help so far guys!
 
Reply
Old Feb 10, 2010 | 08:16 PM
  #11  
starmilt's Avatar
starmilt
Post Fiend
Joined: Oct 2007
Posts: 10,501
Likes: 5
From: Faibanks Ak.
Here is a thought it has been a few years since I have changed a core in one of these, and I can't remember if they set in the foam padding that went around some of the cores or not. If so we used to have trouble with the foam disintegrating and it had to be replaced for the heater to be effeciant.
Yea I know exactly where eagle river is I hang out at fairbanks but get through there some.
 
Reply
Old Feb 10, 2010 | 09:15 PM
  #12  
AlaskanCummins's Avatar
AlaskanCummins
Thread Starter
|
New User
Joined: Jul 2008
Posts: 19
Likes: 0
From: Alaska
You may be onto something starmilt, as the core that I'm in possession of does have the foam around the sides and bottom. Only the top doesn't have it. Maybe it disenegrated and there is a gap letting cold air pass by the core.

I just wish I could see in the box w/out removing it!
 
Reply
Old Feb 10, 2010 | 09:50 PM
  #13  
Bullitt390's Avatar
Bullitt390
Certified Thread Hijacker
20 Year Member
Photogenic
Liked
Joined: Aug 2001
Posts: 14,441
Likes: 59
Club FTE Silver Member

There is a pre-formed foam padding that goes around the core to seal it in the heater box.

But like Montana said, I have the standard heater and it will roast you. I love the looks on people's faces as I pass them wearing a t-shirt and they are in their Toyota Camry's all bundled up.

The heater works so good, That I can turn the fan OFF and just have the ram air effect thru the cowling heat the cab plenty at 50 mph.

Josh
 
Reply
Old Feb 10, 2010 | 10:01 PM
  #14  
moose4x4's Avatar
moose4x4
FTE Emeritus
20 Year Member
Liked
Loved
Community Favorite
Joined: Jan 2006
Posts: 2,288
Likes: 200
From: springfield Missouri area
Originally Posted by AlaskanCummins

I just wish I could see in the box w/out removing it!
Check with some local auto shops, diesel shops, most have a small flexible tube with camera on it to see inside engines, You might be able to borrow or rent. Home depot also has one for sale not sure how much, used to check inside walls and such.
 
Reply
Old Feb 10, 2010 | 10:19 PM
  #15  
AlaskanCummins's Avatar
AlaskanCummins
Thread Starter
|
New User
Joined: Jul 2008
Posts: 19
Likes: 0
From: Alaska
That's a good idea Moose - I didn't even think of that and I'm in the HVAC business!

A "snake-light" would work good - maybe all I'd need is a 3/8" hole or so to get the camera/lens end it to take a look see.

That's why I love these forums - so many good ideas!
 
Reply



All times are GMT -5. The time now is 03:34 AM.

story-0
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-1
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-2
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-3
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-4
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-5
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-6
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-7
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-8
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-9
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE