Upgrade, 1-3/8" Radiator locally for most folks...

[Iron Indian]

Hey guys,

I got a 1999 Pontiac Grand Prix GTP and upgraded to a 1-3/8" radiator. The radiator listed in this post will bolt directly in a Grand Prix with a couple slight modifications that anyone can do. The install is straight forward and easy, one of the those most simple mods you can do and one of those most benifical too, especially for you intercooled guys.

Here's what I got...

I went to my local O'Reillys Auto Parts store and got me a new aluminum Proliance Radiator PN: 432387. If for some reason they cannot access this PN (they should have no problems) the radiator is for a 1998 Chevy Monte Carlo, 3.8 Liter V6 N/A, and there will be 3 choices for the radiators... a 5/8", 1", and a 1-3/8" HD listed on the computer. If its not in stock it'll most likely be at the local HUB, you should get it the same day most likely. Before buying the radiator, take you tape measure and double check the core size! The first one they got for me was 1", but the sticker had the correct PN on it. They got another one and it was correct, double check this before purchasing! The radiator cost me $186.99 and w/ tax that came out to $202.65. It comes with a LIFETIME Warranty which is worth its weight in gold IMO. If something fails on it, a replacement is a few hours from me at all times. This is important to some people, especailly those with daily drivers.

I just did a write up on how to install/modify it to fit here: http://www.grandprixforums.net/f73/c...rade-3697.html

Don't go with stock when you can get a nice upgrade for the same price and only need to do very minimal and painless modifications.

Hope you guys enjoy this upgrade!

[02BlueGT]

Good find, the community thanks you

[Iron Indian]

Actully thank Rook (i think thats his SN?). He told me about it, i'm now telling everyone else about it + did a write up

[JoshMcMadMac]

This is an awesome upgrade, but I do have a question. The part number you list shows as only 1" thick...is the information wrong, or maybe you have the number off?

Proliance Online Catalog

[Iron Indian]

I double checked everything, the number above is correct and according to OReillys the PN above is for the 1-3/8". I donno which is wrong. I know for a fact mine is a 1-3/8" (measured it) and it has that PN on it. I donno, somebody is wrong... OReillys or Proliance...

[JoshMcMadMac]

I double checked everything, the number above is correct and according to OReillys the PN above is for the 1-3/8". I donno which is wrong. I know for a fact mine is a 1-3/8" (measured it) and it has that PN on it. I donno, somebody is wrong... OReillys or Proliance...

But you did measure the fins specifically at 1-3/8"?

[Iron Indian]

Yes the core is 1-3/8", not measuring the side tanks, i'm measureing the core itself (what you're suppse to measure). My stock GTP rad was 1", my new radiator is 1-3/8" with PN 432387 on it. Measured everything about 3 times before doing anything.

[Iron Indian]

Just called OReillys. I had them look up a 1998 Monte Carlo, 3.8L... They of course had 3 radiators listed, here is what they had for part numbers for that car...


5/8" Radiator = 432426
1" Radiator = 432427
1-3/8" Radiator = 432387 <------------(The Radiator you want.)


Since something ain't right somewhere, heres what I recommend. Go to your OReillys store, look up radiators for a 1998 Monte Carlo 3.8L, they will have 3 choices of radiators and they should ask you what size do you need. Ask for the 1-3/8". Whenever they get it to you, before buying it or taking it home, measure it. Take a tape measure with you and mesaure the core itself to ensure you get the correct core for your application. If your core measures 1-3/8", you're good to go.

Good Luck...

[JoshMcMadMac]

Awesome, thanks for the footwork on this Shawn!

[JoshMcMadMac]

Rockauto has 432387 listed for $147.79. Throw in the 5% discount and it is down to $140.40, and the shipping to me zip code was $12.45.

PartsAmerica has it for $145, which means you can probably get it at your local Advance Auto Parts / Checker Auto Parts / Schuck's Auto Supply / Kragen Auto Parts / or Murray's Discount Auto Parts stores.

[Iron Indian]

I couldn't get it at Advanced here. They only sell the 5/8" and 1" and there the same price as OReillys.

Also keep in mind, OReillys offers a Lifetime warranty with theres which is worth the extra money IMO. I'm keeping my car and I like knowing I can get a replacement part down the street from me. I donno how many people care about this, but I do. Lifetime parts FTW.

Also PRJ warned me awhile back, people were ordering radiators listed as 1-3/8" from Rock Auto (i think) and they ended up getting the 1" rad instead. Be sure and double check whatever you order. After hearing of these problems I decided to find a source locally so I can physically see and measure it before buying it and having to dick with shipping and a middle man. I hate ordering stuff and getting the wrong stuff, it really pisses me off.

Hope whatever you guys do works for you.

[JoshMcMadMac]

I couldn't get it at Advanced here. They only sell the 5/8" and 1" and there the same price as OReillys.

Also keep in mind, OReillys offers a Lifetime warranty with theres which is worth the extra money IMO. I'm keeping my car and I like knowing I can get a replacement part down the street from me. I donno how many people care about this, but I do. Lifetime parts FTW.

Also PRJ warned me awhile back, people were ordering radiators listed as 1-3/8" from Rock Auto (i think) and they ended up getting the 1" rad instead. Be sure and double check whatever you order. After hearing of these problems I decided to find a source locally so I can physically see and measure it before buying it and having to dick with shipping and a middle man. I hate ordering stuff and getting the wrong stuff, it really pisses me off.

Hope whatever you guys do works for you.

I totally understand where you are coming from. I was simply posting the information for those of us who are not blessed with O'Reilly's.

[SC Drew]

Just did some checking. That rad was optional in all the previous Gen of W-bodys. Here is the list from Rockauto of all the models that rad is used in.
CHEVROLET LUMINA (1994 - 1996)
CHEVROLET LUMINA EURO 1994
CHEVROLET LUMINA LS (1995 - 1996)
CHEVROLET LUMINA LTZ 1997
CHEVROLET LUMINA Z34 1994
CHEVROLET MONTE CARLO 1999
CHEVROLET MONTE CARLO LS (1995 - 1998)
CHEVROLET MONTE CARLO Z34 (1995 - 1998)
OLDSMOBILE CUTLASS 1997
OLDSMOBILE CUTLASS GLS 1997
OLDSMOBILE CUTLASS SUPREME (1994 - 1997)
OLDSMOBILE CUTLASS SUPREME S 1994
OLDSMOBILE CUTLASS SUPREME SL (1995 - 1997)
PONTIAC GRAND PRIX GT 1995
PONTIAC GRAND PRIX GTP 1995
PONTIAC GRAND PRIX SE (1994 - 1996)