[3 Deuce 64]

Tom the earliest 64 GTO core support that I have and can document is first week of February , the latest is mid July . Those are all the same . Next point we know in 64 the core support was GTO specific or at least the seven 64 GTOs I've owned all had the squared off bottom core support wether it had the 3 or 4 core rad . On the other had the numerous tempests and Le Mans that I acquired had the rounded bottom core support . I have to say at this point I never owned a 64 A/C car so I can't say wether or not a tempest that came with factory A/C had the squared off bottom core support which took the 17 in rad . I'm going to assume at this point because I can't get to the tempest core support because of a few feet of snow cover that the top section of both core supports are the same . I've only had one 64 GTO with the Hd 4 core rad and that is my Tri Power 4 speed convertible and it shows up on my PHS as being ordered. That car still retains the original Harrison rad .Another point to mention is the top hold downs are different and location specific . If my memory serves me correctly the mounting holes in the bracket will only line up with the specific application 2&3 core hold down to the passenger side of hood latch with welded in nuts and 4 core to the drivers side with the snap in caged nuts . Unfortunately because of the snow I can't get to a lot of the parts to take pictures for verification .

[John V.]

Tom, yes I think we are in agreement. The key for the tall 2" Rad anyway seems to be not the trans per se, rather it is whether the Rad had the oil cooler (regardless if it was plugged for a Man Trans or used for an Auto Trans). If oil cooler, then bracket at welded nuts.

I was just surprised because I figured the filler neck would be in the same position for the 2" Rad with or without the oil cooler.

My car is fairly early, 11D from Fremont.

It has the sq. holes in the brace for the caged nuts. So seems to me, the sq. holes were needed for some reason from the start even if the Man Trans GTO Rads were not yet in production.

And since my 4 spd build did not apparently get a Man Trans Rad, plus the late Dec. '63 Inspector's Guide makes no reference to the Man Trans Rad (2" or 2-5/8"), I assume they were not yet in production.

However, there were 8 other Tempest Rads being used in production.

Maybe 1 or more of them also had the "alternate" filler neck location and required the sq. holes and caged nuts in the brace. And it would have been simpler for PMD to punch the holes in a single design brace rather than have different braces for different applications.

As I mentioned in an earlier post, perhaps the only explanation for why the two different filler neck locations were used for the 10 different '64 Tempest Rads used in production was because they are the standard arrangements Harrison offered.

Some had the filler neck in one position, others had it in an alternate position.

Looking at all of the '64 Tempest Rad choices, I'm wondering if the short 2" Rad used with the 2 bbl 326 & Man Trans (Code 55, no oil cooler) might have used the alternate filler neck position.

This Rad is listed in the Inspector's Guide but the usage description is in error.

It shows for use with Auto Trans, should show with Man Trans since it did not have an oil cooler and all 326 Auto Trans were water cooled. The Inspectors Guide correctly indicates the short 2" Rad Code 53 ALSO for the 2 bbl 326 with Auto Trans, it has an oil cooler and obviously they can't BOTH be for the one application.

Whether the Code 55 or some other Rad, I'm guessing one or more '64 Tempest Rads had the alternate filler neck position and the reason was simply because that is how Harrison designed them for reasons of their own, PMD didn't get to control it.

I would also have guessed that the most common Rads were able to use the welded nuts but since the Code 50 2" Rad for the Man Trans 389 had the alternate filler neck position and it was pretty common once it came into usage, I can't even claim that the most common Rads used the welded nuts.

Still will be useful to learn which arrangement was used for the Auto Trans 2-5/8" Rad if anybody knows.

[John V.]

Don, yes the A/C Tempests with V8 used the same tall Rad and core support as the GTO.

Only the GTO used the tall 2" Rad. The A/C Tempests with V8 got the tall 2-5/8" Rad, used early year for all Tripower and also the HD Rad option for the GTO, including the late year Tripower. The HD Rad was also required with 3.90 axle and might also have been required with the optional 3.55 axle once the Tripower was revised in Jan from 3.55 as standard to 3.23 as standard.

I think when you get a chance to check, you will find as I did on my own GTO core support, the mounting hole spacing for the brackets is the same 2" center to center regardless if they are screwed down at the welded nuts or at the sq. holes with caged nuts.

The only limitation is the location of the filler neck.

The brackets are specific to the Rad thickness from what I can tell, but the mounting holes in them would allow them to screw down at either location if not for the filler neck interference.

Check it out when you can, I'm looking for confirmation.

[remy30006]

Sorry to jump in on this thread but I am trying to find the correct upper hold down for my car. By looking at all the pictures and reading the thread there must have been different hold downs for different radiators? Slotted ones with 2 inch hole spacing and non slotted with 1 5/8 inch hole spacing?

[Old Man Taylor]

Mine is like the one on the left.

[remy30006]

That's the one that came on my car but it is chrome so Im assuming somebody had that done I bought the one on the right thinking it was correct for all 64s but doesn't seem to fit with my set up.

[Brad_bb]

And still no one has posted a picture of the original caged nuts?

[mwritter]

Bringing this back up as I'm in need of a set of the caged nuts (or at least a picture if I'm going to try my local hardware store). If Ames has them, I can't seem to find them online or in the catalog.

[JAKE 64]

For 1964

mwritter:

I believe you are looking for these black phosphate coated cage nuts.

I believe our host sells these as Part No. P148, and are listed as a '65 Hardware Kit.
AMK Products (540-662-7820) on page 56 of their 2013 catalog, may get you close.

[mwritter]

Originally Posted by JAKE 64

For 1964

mwritter:

I believe you are looking for these black phosphate coated cage nuts.

I believe our host sells these as Part No. P148, and are listed as a '65 Hardware Kit.
AMK Products (540-662-7820) on page 56 of their 2013 catalog, may get you close.

Thanks Jake 64 - huge help. I was searching under '64 only and since these are listed as 65-7 they weren't coming up. I appreciate you taking the time to post!