Which radiator for an '85 TA Heavy-Duty system?
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Joined: Jun 2020
Posts: 14
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From: Salem, Oregon
Car: 1985 Pontiac Trans Am WS6
Engine: LG4 305/5.0L V8
Transmission: 700-R4
Axle/Gears: 3.08
Which radiator for an '85 TA Heavy-Duty system?
My '85 Trans Am WS6 is in need of a new radiator; the original has sprung a bad leak. In order to keep the car looking as close to original as I can, which heavy-duty radiator would the Third Gen faithful recommended? Thank you in advance.
Joined: Aug 2011
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From: Jackson NJ
Car: 1984 T/A
Engine: LQ4
Transmission: T56
Axle/Gears: Ford 8.8 4.10 gears
Re: Which radiator for an '85 TA Heavy-Duty system?
a stock replacement radiator works just fine. you should try to flush out the block when you replace it as well.
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Junior Member
Joined: Jun 2020
Posts: 14
Likes: 1
From: Salem, Oregon
Car: 1985 Pontiac Trans Am WS6
Engine: LG4 305/5.0L V8
Transmission: 700-R4
Axle/Gears: 3.08
Re: Which radiator for an '85 TA Heavy-Duty system?
Hey, Punkmaster98, yeah, doing the engine block flush is a good habit to get into. So the AC Delco radiator is going to set a guy back 5-bills, and I just have a hard time shelling out that much for a part I use to buy at the salvage yard for $20. O'Reilly's has a stock replacement for $150 that looks pretty good. I might go that route. Thanks for the reply! 247spin
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From: Franklin, KY near Beech Bend Raceway, Corvette Plant and Museum.
Car: 1992 Pontiac Firebird
Engine: 5.0L L03 TBI
Transmission: 700R4
Axle/Gears: 2.73
Re: Which radiator for an '85 TA Heavy-Duty system?
A few members here seem to be happy with this OSC 951 radiator. @midias @Catbox
This radiator is 26.25" x 17.25" and has a 1.25" thick core and is marketed as a 2 row equivalent. I checked the normal parts stores Advance Auto Parts, Auto Zone, NAPA, and O'Reilly Auto Parts and the radiator they sell is a 26.25" x 17.25" x 1.00" single row.
Cheap dual core radiator - Third Generation F-Body Message Boards
OSC Automotive Products 951 OSC Automotive Radiators | Summit Racing
OSC Automotive Products 951 OSC Automotive Radiators | Rock Auto
This radiator is 26.25" x 17.25" and has a 1.25" thick core and is marketed as a 2 row equivalent. I checked the normal parts stores Advance Auto Parts, Auto Zone, NAPA, and O'Reilly Auto Parts and the radiator they sell is a 26.25" x 17.25" x 1.00" single row.
Cheap dual core radiator - Third Generation F-Body Message Boards
OSC Automotive Products 951 OSC Automotive Radiators | Summit Racing
OSC Automotive Products 951 OSC Automotive Radiators | Rock Auto
Last edited by Airwolfe; Apr 22, 2025 at 09:10 PM.
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From: Henrietta NY
Car: 1984 Trans Am L69
Engine: Sniper EFI Powered 355
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: Which radiator for an '85 TA Heavy-Duty system?
The OSC is the only 1.25 two core I have found the rest seem to be 1"
So far so good cooling my car well and has the same construction as my factor one did
So far so good cooling my car well and has the same construction as my factor one did
Last edited by midias; Apr 22, 2025 at 08:22 PM.
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 14
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From: Salem, Oregon
Car: 1985 Pontiac Trans Am WS6
Engine: LG4 305/5.0L V8
Transmission: 700-R4
Axle/Gears: 3.08
Re: Which radiator for an '85 TA Heavy-Duty system?
I measured the old GM radiator and it's the exact same size as the OSC 951, which is great. Because my car has AC, installing a radiator with a 1.00" single row would just be asking for trouble. Thanks so much for this information, Airwolfe, I really appreciate it!
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 14
Likes: 1
From: Salem, Oregon
Car: 1985 Pontiac Trans Am WS6
Engine: LG4 305/5.0L V8
Transmission: 700-R4
Axle/Gears: 3.08
Re: Which radiator for an '85 TA Heavy-Duty system?
Good to know, midias, thank you! I believe I'll be going with the OSC 951.
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From: Michigan
Car: 1987 Camaro Sport Coupe
Engine: 427ci Gen 1 Small Block
Transmission: 700r4
Axle/Gears: Strange60 4.10 Eaton Truetrac
Re: Which radiator for an '85 TA Heavy-Duty system?
I recently got a champion 2 row for $250, it's all aluminum so no worries about the plastic tanks cracking. I haven't installed it yet but the sticky seems to say they fit with no modifications.
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Car: 1986 IROC Z
Engine: 5.0 TPI
Transmission: 700R4
Axle/Gears: 3.23 Posi
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From: Missouri
Car: 1985 Z28
Engine: 305 LG4
Transmission: T5
Axle/Gears: 3.42
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From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Which radiator for an '85 TA Heavy-Duty system?
This is the one I got:
https://www.griffinradiator.com/load...key_id=6-70311
https://www.griffinradiator.com/load...key_id=6-70311
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From: az
Car: 91 WS6 GTA
Engine: 5.3
Transmission: 4l60e
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From: Colorado USA
Car: '83 Firebird (T/A Clone)
Engine: 350 with L-69 components
Transmission: 700R-4, 2000 RPM stall converter
Axle/Gears: 10-bolt/3.73 ..
Re: Which radiator for an '85 TA Heavy-Duty system?
Joined: May 2020
Posts: 289
Likes: 75
From: Michigan
Car: 1987 Camaro Sport Coupe
Engine: 427ci Gen 1 Small Block
Transmission: 700r4
Axle/Gears: Strange60 4.10 Eaton Truetrac
Thread Starter
Junior Member
Joined: Jun 2020
Posts: 14
Likes: 1
From: Salem, Oregon
Car: 1985 Pontiac Trans Am WS6
Engine: LG4 305/5.0L V8
Transmission: 700-R4
Axle/Gears: 3.08
Re: Which radiator for an '85 TA Heavy-Duty system?
Doh! I already ordered the OSC 951 at Rock Auto for $105. 
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