[Dick Boneske]

Was a heavy duty fan and radiator (4 core) required when Tripower was fitted to a '64 GTO at the factory? There have been many posts in the Heating/Cooling Forum about overheat problems. There is a recent one posted by 65vette with a newly rebuilt engine and Tripower that runs too hot. He has a 3 core radiator.

Anyone know for sure what the factory specified?

[Pontirag]

Factory specified a taller 4 core radiator with a steel shroud. There is a lot more to the overheating issue than a biggie sized radiator. Its been done to death over there.

[Dick Boneske]

The OP question was: Did Pontiac require 4 core radiators (Heavy Duty Radiator and Fan) in factory Tripower '64 GTO's?

[Pontirag]

"anyone know for sure what the factory specified"

"Factory specified a taller four core radiator with a steel shroud"

Yes?

[VergeGTO]

I thought that the HD radiator was an option for the tri-power? At least it shows that way on my PHS docs. I think it came standard when AC was chosen. Perhaps it was "recommended" when a non AC tri-power was added to the mix.

[Dick Boneske]

That's the question. Was the "Heavy Duty Radiator and Fan" mandatory with Tripower? It was mandatory with the 3.90 axle ratio, but it came without a shroud on 4 bbl. cars. I know because I bought one.

[Old Man Taylor]

I tried ordering a heavy duty radiator with mine. It was eliminated from the cost as the tri-power cars came with the heavy duty radiator. A 4 row with the taller core. There was no shroud in '64.

[Tom Vaught]

All I know is that my 64 GTO has the deep "squared off" 4 core radiator support and came with the Harrison 4 core radiator. I now have a 5 core brass radiator in the car I want to try vs using an aluminum piece. The radiator uses the 4 core tanks but has one more core thickness.

The car did not come with a shroud, I later adapted a plastc GTO part off of a later car but will probably use a modified steel big car 4 core type shroud with the 5 core radiator in the GTO.

You probably figured out that I like to experiment with parts that appear "stock" but are improved pieces.

Tom V.

[Dick Boneske]

Tom & OMT,
Thanks for the responses. Anyone else have a '64 with factory Tripower that DIDN'T have a 4 core radiator from the factory? It appears that all '64 Tripower GTO's had the heavy duty radiator and fan whether you ordered it or not. I also don't recall seeing one with a fan shroud--except with factory A/C.

[tripwr1964]

I was looking at my invoice (sticker). The Tripower and HD radiator are listed separately, they weren't bundled. So, you must of had to check the rad, if the 3x2 was ordered. $12.91 for the 4 core radiator, those were the days.

[Pontirag]

page 97 in Zazarine and Roberts "Pontiac Restoration Guide" shows the shroud.

I have owned several. AC and Tripower cars had the bigger 4 core radiator and the shroud. also according to Zazarine and Roberts it was sheet metal.

[John V.]

Dick, from research I have done for the '64 Kansas City and Baltimore cars (Rad Manifest Codes found on the PHS docs) and knowing what the '64 Tempest Inspector's Guide calls out for Radiator usage as of the Dec. 19, 1963 compiling Engineering Releases thru that date, plus looking at the '66 MPC Rad usage listing, I can tell you that I have seen a variety of usages associated with the Tri-Power cars and I don't know if anybody will be able to say what was done with certainty throughout the year.

At the time of the printing of the Inspector's Guide, there was a Rad listed for 4 bbl 389 usage without A/C, code 57 with Trans Oil Cooler, 17.5" x 2" with .18" fin spacing. The Tri-Power Rad, also with Oil Cooler, was listed as the code 58, 17.5" x 2.63" with .18" fin spacing. This same Rad was used with the 326 or 389 when A/C was ordered.

There was no listing at that time for a Manual Trans specific Rad without Trans Oil Cooler. However, Rads for that application were released at some point and used. These were code 50, fin spacing unknown, but same 17.5" x 2" and specified for the Man Trans 4 bbl w/o A/C. The code 59, 17.5" x 2.63", fin spacing unknown, was specified for the Man Trans Tri-Power w/o A/C and also was used with the 326 or 4 bbl 389 with Man Trans and A/C.

The Auto Trans Rads could be substituted for a Man Trans application, the Oil Cooler ports were left plugged, but of course, the Man Trans Rads could not be used for an Auto Trans application. Presumably the Man Trans Rads were released because they were cheaper w/o the Oil Cooler.

I have documented one very late built KC GTO with Man Trans & Tri-Power that shows the Rad code as 50. This may have just been an oddity put together at build out that "violated" the Rad usage rules because of availability. Or maybe it indicates that there was a change in usage specified during the year.

I do not know if a Heavy Duty Rad option was generally mandatory when 3.90 gears were ordered in a 4 bbl or Tri-Power. However in the only '64 GTO (Fremont built) that I have ever documented that was ordered with the Special Equipment code 8 close ratio M21 4 speed, the original Window Sticker (not a repro) for the car listed all of the mandatory extra cost optional equipment that was known to be required if the close ratio (a very late year release for '64) was to be ordered. That extra equipment included GTO option, Tri-Power, 3.90 Axle Ratio with Safe-T-Track and Metallic Brakes (code P axle) Heavy Duty Radiator, and Heavy Duty Fan. The close ratio was never mandatory for such a combination, but if the close ratio was ordered, all of the rest was mandatory.

The latter two options are strange because there is no indication that Pontiac released a specific Rad considered to be HD for this application. My speculation is that it was the code 59 Rad but with a shroud and seals that may have been omitted except on A/C cars. In other words, nothing special about the Rad itself, just the added pieces to improve cooling efficiency. I have not even tried to understand what was special about the HD Fan. On the Window Sticker, the HD Rad was listed at $12.91, the HD Fan was listed at $3.12. Sales codes were 432 and 644 respectively and could be ordered on the All Series Special Equipment Order Form.

With the exception of the one very late built Tri-Power that seems to have been built with the 2" Rad, generally I have found the T-P GTOs to have gotten the 2.63" Rad as standard. So I figure the "Heavy Duty" Rad option only affected the shroud and seals when it came to the T-P application, not the Rad itself. Just my opinion.

[Dick Boneske]

The '64 GTO I ordered 4-22-1964 was a 325 HP (4 bbl.) with 3.90 rear gears. As you can see from the attached order, the 3.90 rear end was part of a package for $75 that included Safey Track, the heavy duty radiator, metallic brakes, and speedometer adaptor. The car had no radiator shroud. The only '64 GTO's I saw back then with shrouds were the ones with factory A/C.

The heavy duty fan in '64 differed from the regular fan. The HD fan had seven unpainted aluminum blades with straight tips. The regular fan had black painted blades with curved tips.

I remember my car payment was $76 a month. Those were the days!!

[3 Deuce 64]

my 64 tri power 3.23 4 speed came with and still has the original 4 core harrison in it . no fan shroud but I added the factory clip nuts to the core support and a 66/67 shroud 32 years ago when I bought the car.It ran on the hot side until I did that. It still has the original aluminum curved tiped fan with original clutch

[John V.]

Dick, order paperwork a bit tough for me to read. But option descriptions can be deceiving.

For example, the mandatory additional equipment with the 3.90 gears shows the "Speedo Adaptor" as you pointed out. However, you may not be aware, but with 4 spd., no speedo adaptor was ever used. A specific wide ratio trans, p/n 9774826 was used since it was assembled with the internal 6 tooth speedo drive gear. Without 3.90 gears tranny p/n 9774825 was used with the 8 tooth speedo drive gear.

The 3.90 gears were available in almost all A bodies, including certain 6 cyl applications where a standard brake peg leg could be used. For the 4 bbl 326, 4 bbl 389, and T-P cars, however, the only 3.90 axle available was the code 3P which was strictly Safe-T-Track with Metallic Brakes.

A 4 bbl 326 or 4 bbl 389 would not have automatically gotten the HD Radiator, so the addition of the HD Rad when 3.90 gears were ordered would be at extra cost. However, the Tri-Power already required the HD Rad at extra cost. Adding the 3.90 axle to a Tri-Power car still "required" the HD Rad, but it was the same Rad and same added cost as was already going to be reflected on the Invoice and Window Sticker, so no actual change.

As to the Fan, I am not aware of a running change in '64 affecting the GTO fan and fan clutch. AFAIK, the original std. GTO fan was 7 blade, 18" dia. and p/n 9775582 with Clutch p/n 9775578 exc. with A/C. This fan & clutch was not used for any other '64 factory application that I am aware of.

Same fan was used for the T-P GTO.

For the GTO with A/C or special equipment option Sales Code 644 Heavy Duty Fan, a 7 blade 19.5" dia. Fan p/n 9775580 with Clutch p/n 9775579 was specified. This Fan & Clutch was used for all A body with V8 & A/C. However, it was NOT the HD Fan for the 326 applications.

You mention the straight vs. curved tips and unpainted vs. painted blades. I am unfamiliar with those distinctions.

Although the Clutch p/ns did not change and the Clutch itself was separately serviced, the Service Replacement p/ns for the GTO Fans became 9777013 for the 19.5" dia. and 9777014 for the 18" dia. I do not know why these p/ns changed from what I know of the factory installed p/ns except that perhaps Pontiac did not service these Fans except as an assembly with the Clutch installed. I cannot imagine another explanation for why the Fan p/n itself would have changed. I do not think there was a running change affecting the factory fan p/ns during '64.

I do not know of the existence of an even "heavier" duty Fan or Clutch that may have been used when the close ratio trans was specified.

Having looked at a few original T-P GTO Window Stickers, I suspect that the HD Rad was always listed separately as an "automatic" extra cost line item whenever T-P was ordered. In other words, you didn't have to check it off in the order, but you would get it anyway and it would be priced separately from the T-P option. Same when you ordered 3.90 axle, with or without T-P, HD Rad was listed separately as a line item. That doesn't explain the one very late built T-P GTO that lists the regular GTO Rad code 50 on the Manifest (no Window Sticker to check), but it generally explains why HD Rad would be priced separately from any other option on the Window Sticker. That way, you never paid for it twice, even though it was required with two different options (T-P & 3.90 axle).

That would also explain why the car with the close ratio trans shows the HD Fan at extra cost on the Window Sticker. The T-P GTO did not get the bigger Fan unless it could be special ordered (see below) or if the car got A/C.

With close ratio, the bigger Fan was mandatory, so it was listed as a line item.

A/C was not available with the 3.90 axle and V8. You could order the code P 3.90 axle with Man Trans 4 bbl 326, any 4 bbl 389, or any T-P. You got the bigger Rad with any of these but no shroud. But if you ordered the close ratio trans, you had to take a lot of other stuff, including the HD Fan (and maybe a shroud, see below).

So if you wanted to improve the cooling efficiency of any GTO, you could do what 3 Deuce 64 did and add a shroud. And if you did not have the 2.63" thick Rad, you could swap to that. And you could also add the bigger Fan.

Incidentally, you could add A/C as a Dealer Accessory Package. From what I can tell, the field installation included adding the 18" clutched Fan that was standard in the GTO. It also included a specific shroud and seals set-up, shroud sized for the smaller Fan as compared to the Factory A/C set-up. Since the GTO already had the same Fan as was to be installed with the Package, I'm not sure what was done with the Fan that may have been in the Package but I don't think there was a GTO specific A/C Package, so the GTO Owner was cheated a bit, I suspect, while the 326 Owner got a new Fan installed. The reason the Package did not use the 19.5" dia. Fan was because the 326 applications had the shorter Rad. It might have made sense to have a GTO specific A/C Dealer Package that would have included the bigger Fan & Shroud, but Pontiac apparently didn't elect to offer that, perhaps because there would have been very little demand.

Dick, I'm not sure about the terms 4 core & 3 core. But I think this relates to the 2.63" thick and 2" thick GTO Rads. So based on what I think is true, the Tri-Power was specified with the HD 2.63" thick Rad (I am aware of at least one late year exception) but the standard 18" clutched Fan. The shroud was only added with A/C (I believe with trailering options also), and was not available as a separate factory option. The HD Fan was required with the late year close ratio trans option. The HD Fan was a special equipment option, Sales Code 644 on the All Series Special Equipment Order Form.

There is one caveat to this latter claim. In '65, the HD Fan was not offered as a separate option for the GTO. It still was required with the close ratio trans option.

It occurs to me that Pontiac may not have wanted to offer the 19.5" dia. Fan in a GTO without the shroud, so they simply did not allow the HD Fan available as a separate option with the GTO. Very possibly, when the close ratio trans was ordered, you were required to order the HD Rad & HD Fan and what you got was the same Rad set-up and Fan as you would have gotten with A/C; shroud, seals, and all. Perhaps Pontiac thought it was a bit unsafe to have that large Fan not surrounded by a shroud, but with close ratio trans treated it same as if A/C or a trailering option had been ordered.

If so, then you will never see the HD Fan option on a '64 GTO unless it was optioned with the close ratio trans. In fact, as I think about it, this makes the most sense from the evidence I have seen.

It would be pretty easy to improve the cooling efficiency of any GTO by making use of the components from any '64 V8 with A/C.

[Tom Vaught]

Great Discussion!

Tom V.

[Dick Boneske]

Ditto! And, thanks Tom for the lengthy discussion of various possibilities. You've related some great info. The heavy duty fan on my new '64 GTO was different from most others I remember from that time. As I said, it had unpainted, curved, straight-ended aluminum blades with no bends on the tips. It looked like the fans on '68 and later GTO's. All the other '64's I remember had black, curved, painted blades with bends on the ends of the tips.

[John V.]

Dick, not sure what I was thinking yesterday. On the Pontiac Plant Manifest records, a GTO with 3.90 gears DOES show Sales Code 644 for the HD Fan.

Since yours came that way and no shroud, looks like I misguessed about the availability of the HD Fan as a separate option for the GTO.

Can you confirm that the Fan you describe is 19.5" dia.?

Assuming it is, your 4 bbl car and the Factory Axle Usage chart in the Inspector's Guide (a lot more detail than the Axle Chart in the GTO Sales Brochure) all point to the fact that the 3.90 was available with either engine and all 3 trannies with the GTO, and the mandatory HD Rad & HD Fan additional option requirements were same for the 4 bbl GTO, as for the T-P GTO, when 3.90 was special ordered. I don't have a copy of a 4 bbl GTO Manifest with 3.90 axle, but the Pontiac Plant T-P Manifests that I do have that show 3.90 axle all show Sales Code 644 for the HD Fan and Sales Code 432 for the HD Rad on the Manifest.

I only have one Pontiac Plant Manifest for a GTO with A/C. It does NOT show Sales Code 644 or Sales code 432 (which it certainly was built with), so I now conclude that the HD Rad & HD Fan (with shroud & seals) were included in the A/C option and would not have been separately listed on the Window Sticker for an A/C GTO. But for a GTO with 3.90 axle, the HD Fan & HD Rad do show up on the Window Sticker, at least on the Fremont example I have.

Yesterday, I speculated that you might not be able to order Sales Code 644 to get the 19.5" dia. Fan on any GTO as a separate Option.

I now conclude that the HD Fan was an available Special Equipment Option in '64 for the GTO even though in '65 (Sales Code was changed to 534 on the '65 ASSE Order Form) the HD Fan shows N.A. with GTO.

Dick, your Dealer Order Paperwork didn't identify the HD Fan. But I wonder if you have the original Window Sticker (I don't trust the repros, they are not very accurate) still and does it show a line item for HD Fan & HD Rad?

The Pontiac Plant Window Stickers were set up differently than the Fremont Plant Stickers. So no telling if the HD Fan & HD Rad were broken out as line items when 3.90 axle was ordered, but if you have the Sticker, it would be interesting to know if they were. Even the descriptions could be different. At Fremont, there was a typo, it reads "K08 FAN HEAVEY DUTY 644". Aside from the misspelling of heavy, note the use of the UPC K08. The Pontiac Plant did not use UPCs, Fremont was a B-O-P Plant and UPCs were used at the B-O-P Plants.

But the K08 designation is a bit interesting too. In the Inspector's Guide, the Sales Code 644 HD Fan shows the UPC as K01 with a note indicating "326 Engine". The HD Fan for the 326 Engine was a different Fan than what the GTO used as I mentioned yesterday. In fact it was a 5 blade Fan. I don't know anything else about it except the p/n and it used a Spacer and was not a clutched Fan. With A/C, the 326 cars got the same 19.5" dia., clutched Fan as the GTOs got.

So it seems, although the Sales Code was 644 in either case, I would guess the UPC for the HD Fan for the 326 was K01 and for the GTO it was K08.

And now I see I jumped to the wrong conclusion about the Tri-Power Radiator usage also!

I thought I had checked a sufficient no. of records. I mentioned one exception. But going back thru, I see that most of the non-A/C T-P GTOs seem to NOT have the HD Radiator. In fact, the only Pontiac Plant ones that I now can find with HD Rad also show 3.90 metallic brake axle plus one that shows a Special Order 3.55 axle with Safe-T-Track but std brakes.

Can't find evidence that the HD Rad was required for 3.55 axle in the GTO and I have another earlier Pontiac built T-P GTO, also with the same 3.55 Safe-T-Track axle that does not show the HD Rad. So perhaps HD Rad was just special ordered as an independent option on the later one. It is also possible that a running change made the HD Rad mandatory with 3.55 gears later in the year for the GTO. It is noteworthy here to mention that the HD Rad for the 326 engines (Code 54) was 15.5" x 2.63" and was also specified with special order 3.55 and 3.90 axles with 326 engines as indicated in the Dec. '63 Inspector's Guide.

New conclusion, T-P '64 GTOs did NOT get the 17.5" x 2.63" HD Rad as standard content or the HD Fan. If you ordered 3.90 gears, HD Rad & HD Fan were mandatory.

The HD Rad or the HD Fan or both could be special ordered on any GTO as individual options and were listed on the '64 All Series Special Equipment Order Form.

A/C GTOs got the HD Rad & HD Fan, included in the cost of the A/C option.

New conclusions summary:

1. If you wanted the HD Rad with any GTO, you had to special order it. Same for the HD Fan. If you ordered 3.90 gears, HD Rad & HD Fan were mandatory additional options but you did not get the shroud & seals.

2. If you ordered A/C, you got the HD Rad & HD Fan plus the shroud & seals.

And to emphasize, contrary to what I implied in my first post, the Code 58 17.5" x 2.63" Rad is not described as for use with the T-P GTO in the Inspector's Guide. It is now apparent this Rad was only used for V8 with A/C and GTO with special ordered HD Rad.

Going back thru the earlier posts, I realize that my conclusions may contradict what others are claiming.

Pontirag was pretty emphatic that the T-P '64 GTOs got a "taller 4 core radiator with a steel shroud". There is no evidence that there was a taller Rad released specific for the T-P GTO. And lots of evidence that the shroud only came with A/C, no matter what. So can't explain his claim.

OMT, who still owns his '64 GTO, makes a more credible claim. However, when suggesting taller, I suspect he is comparing to the non-GTO 15.5" tall Rads. But ALL GTOs, not just the T-P GTOs got the 17.5" tall Rads. I also believe he Special Ordered the 3.90 axle however. So he should have gotten the HD Rad & HD Fan as a consequence. What is odd is that he says "it was eliminated from the cost as the tri-power cars came with the heavy duty radiator". Perhaps what really happened is that the cost of the 3.90 axle included the cost of the HD Rad and so the separate cost for the HD Rad was eliminated. There is still the question of whether the HD Rad (& HD Fan) appeared as a line item on the Window Sticker. I believe his was also a Fremont build, and the Fremont example that I have does show the separate line ltems for them, so I assume OMTs Window Sticker showed the same. OMT, if you see this, do you still have your original Window Sticker to check?

He also says no shroud in '64, I assume he means without A/C as the A/C cars definitely got shrouds, both the factory installs and as part of the Dealer Accessory Package with the smaller shroud (reportedly fiberglass) to work with the 18" dia. clutched Fan. The smaller shroud was also used for factory installs on certain applications (taxi, police, trailering options).

Tripwr1964 seems to confirm my latest thinking except that there is no way to prove the HD Rad was not mandatory when T-P was ordered even if it is listed separately as a Window Sticker line item. Nevertheless, I now see lots of T-P '64 GTOs that do not show Sales Code 432 for HD Rad, those that do mostly show the 3.90 axle. And same on KC built GTOs with T-P that list the actual Rad manifest code, generally not the HD Rad shown.

And then 3 Deuce 64, has HD Rad with a 3.23 axle and T-P. Doesn't say if he is original owner, where or when built, and what is indicated on the Manifest or Shipping Order doc about the Rad. Also, doesn't indicate the trans, which I have more or less ignored but perhaps the auto trans T-P was treated differently from the man trans T-P. Has the regular GTO 18" Clutched Fan apparently. Was the HD Rad special ordered as a buyer specified added option or was it included because it got T-P? The former would fit my current thinking, the latter would upset the apple cart (could indicate a running change).

Pontirag's reference the GTO Resto Guide is not convincing. That reference is still pretty decent, but it was always mainly a compilation of what was found in Master Parts Catalogs and often got it wrong because of a lack of attention to superseding p/ns and misinterpretations of other MPC listings. And the hobby has learned a whole lot of new stuff since it was published many years ago.

However, just to remind you guys that I am never so sure of myself as to think everybody else must be wrong and I am right, I said this in the 1st para. of my first post in this thread, "and I don't know if anybody will be able to say what was done with certainty throughout the year". Including, and especially, me! In a single thread, I've been able to prove my fallibility.

[Old Man Taylor]

My car did not have the 3.90 rear end. It came with a 3.23 posi. I had a detailed list of the LeMans options so I could order every HD option I could (that I could afford). The order went in with the request for both a heavy duty battery and a heavy duty radiator. When the car was delivered and I completed the purchase, those two items were deleted from my bill. I was told those two items were standard on the T-P cars. I was not able to find my original window sticker the last time I looked for it, but it seems to me that the duplicate one appeared accurate. Plus I think I still have my original Harrison radiator in my shed. What dimensions do I look for to meet the definition of a HD radiator? I thought it was just the core height.

[John V.]

Core ht. is same for both GTO Rads (nominally 17.5"). Core thickness is 2" for the std GTO Rad, 2.63" for the HD Rad. Would be great if you could confirm the original core thickness.

When was it built & which Plant?