[OG68]

Originally Posted by dataway

Will post soon about the upper and lower insulators I got from Ames. Seriously disappointed, not even freakin close. $20 for the insulators and $10 for shipping that could have been sent in a padded envelope instead of a 5x5 box. What a waste of money. What is it with the 68 stuff? Hey .. if it doesn't fit just say so, don't sell us cr*p that doesn't even come close.

I too was disappointed with the Ames product. I ordered the complete set of frame and core support bushings and was underwhelmed by what I received. No comparison with the Inline Tube product which is what I went with. AND THEY FIT and were identical to my originals down to the part numbers.

I appreciate the fact that Ames does a lot for the Pontiac hobby. In the past year or so they have improved their shipping (at least to the West Coast) and come out with some new products. But...I wish Ames would come into the 21st Century with a modern website, delete all the obsolete and discontinued merchandise from their catalogs and accept the fact that there are superior products out there that they don't carry.

For those of us with 68s, or any other year, you must not accept the "fits all 68-72". Do the research before you buy.

[dataway]

Originally Posted by bkmont

Dataway,
Thanks for the write-up. I have one of these older repop supports too. I've modified the upper portion. Now I can copy your modification to get it to sit right.
Bryan

Luckily it's not a huge deal, basic tools, basic skills. Not like replacing a quarter or something. The hardest part is deciding to cut up this $300 part that was supposed to fit from the get go

[OG68]

Thats what's so great about this site is the amount of knowledge here. Plus the various abilities of those who experiment and publish their results as to what works and / or how to modify to make things work. Luckily I don't need a new core support. Just need to repair the bushing hole under the battery. But maybe, just maybe, someone at Ames, NPD, or any other vendor will see this and pressure their suppliers to make the necessary changes.
I'm not holding my breath though.

[dataway]

More minor modifications ...

Here are two locations I decided to go with rivet nuts instead of the OEM sheet metal screws, just don't trust the screws in the Chinesium steel used in the repops.

Two 5/16" nuts used to hold the lower shroud, and two 5/16 nuts for the lower radiator mount hold down locations. Bolts used are grade 5, flange head with an "ultra-corrosion resistant" finish from McMaster-Carr ... they aren't cheap, around a buck apiece but worth it in that location. I'll use anti-seize compound to ensure they never freeze into the rivet nuts. I'll also put a tack weld on the back of the rivet nuts to prevent them from ever getting loose and spinning.

[dataway]

I got a couple of right side lower radiator mounts from Scott. The right side of most auto equipped, V8 tempests with AC had a wide right side mount to accommodate the larger radiator tank size on the right (due to the trans cooler). This is the same size used on both sides of the high capacity radiators used on GTOs with AC and autos (4 core). Most Lemans/Tempest will have the smaller width/length mount on the left side ... so I figured I could modify one of the mounts so I could use it on the left also.

Well ... turns out the both just drop right in to existing holes in the repop support ... not sure if that would be the same with an OEM support ... but you could certainly drill a single bolt hole and make it work.




Here is a right side mount used on the left side, notice the angle of the mount is even correct, tilting the radiator back away from the support at the top.





Here is the bolt hole you use on the left side.





Here is the right side mount in it's normal location.





And the location of the right side bolt hole.





Left side mount installed with rivet nut and 5/16" bolt.


Width measurement of the two mounts, with some very slight slotting of a couple of holes comes in right at 29 7/8" ... exact same as my OEM radiator tanks. I'm not sure of the consistency of either the OEM or the repop bolt hole locations .. but mine only needed to be tweaked about 1/8" to get it just right.

Why I'm making this point is because the right side Lemans/Tempest mounts that will work this way are FAR easier to find than the large left side GTO mounts. I think all 68 and 69 Lemans and Tempests with a V8 and auto used the 3 core radiator, which had these wider four core type right mounts.

[dataway]

By the way, the part number on that bracket is 9790744 ... and the parts book shows it as (2) required in 68 ... meaning they are same for both left and right .... no wonder they worked so well.

PN# 9790744
Group Number 1.274
Car Type P/8-T/8
Description Bracket (lower) (w/211/le" rad)
Qty Req. 2
Start year 1968
End year 1968
Book year 1-25

[dataway]

Some pics fitting the center brace.

I'm probably tilted about a degree too much. The center brace is about 1/4" shy of fitting in. Should be able to massage it in there somehow.

If anyone is doing this same project ... the center brace would come in handy as a guide to help decide how far to tilt everything.

[Chief of the 60's]

When you go over railroad tracks or bumps and see your front sheetmetal shake you will know why GM is better than Chiwanese.

Good luck on the rest of your build.

[dataway]

Please, if you don't have anything constructive to add to this "how to" thread, please don't post.

[Chief of the 60's]

Originally Posted by dataway

Please, if you don't have anything constructive to add to this "how to" thread, please don't post.

That IS constructive as well as an FYI. Point out where it is not. It is a known fact that they are not made as well as the original and what do you think the fenders are bolted to?

[antique69lemans]

After seeing the rework required, how has anyone used one of these as is?! I bought one 10 years ago and noticed it bears little resemblance to the 69 as far as stamping details. Mine was rusted so thin, even a bottom rail wouldn't salvaged it. Excellent write up on what it takes to make it bolt in.

[dataway]

I seriously don't think they can be used unmodified. You can't tilt the whole thing or the bottom radiator mounts and anything else that bolts to the bottom rail will not work. There are probably more than my way to get them to work, but I was shooting for making it as close to OEM as I could. And I still won't really know until it's all installed with fenders.

What motivated me was seeing rusted out originals selling for $1400.

I'm basically working from the blueprints shown in the 69 Assembly Manual. I haven't had a good enough OEM support in my hands to see if what I'm doing is the best solution. And I don't know enough about the differences between the 68 support and a 70-72 support to know why the repops are made this way.

I strongly suggest anyone starting this project do their own research first, but all indications I can find seem to point in this direction.

[dataway]

Battery Tray.
Well I'm pretty sure this is going as planned. Installed a 68 NOS GM battery tray which is designed to sit level when bolted on to the support. Looks great.

Look at the tray and you can see how it's made to fit a tilted core support ... have no idea how a person would bolt this up to an unmodified repop support.

[dataway]

How to locate the finger guard on the core support.



In this photo you see the reference points to use. The repop core support has hidden holes to facilitate this. They are on the top, rear edge .... if you look underneath you will see square punched holes ... that is where GM would have located the square weld nuts on an OEM support. They have to be drilled out on the top side to install 5/16 - 18 rivet nuts, or to accommodate whatever fastener you plan on using (the factory use 5/16-18 machine screws). In this photo you see the hole locations on the repop support and the matching holes on the metal finger guard. (I know they look too far apart ... caused by wide angle lens)





This is what the hole in the repop support look like when drilled out on the top side.






Installing 5/16-18 rivet nuts in the repop support.






5/16-18 screw installed in the repop support.








Finger guard installed using the two reference bolt holes. The additional holes will also need to be drilled out using the finger guard as a template ... you can't see it, but these locations in the repop support also have square holes in the lower layer of metal ... this repop is a mish-mash of 68 and later design features.

Carefully mark the locations and drill for 5/16-18 rivet nuts. They all should be pretty close to the correct location ... a couple of mine did not line up perfectly with the preexisting square holes underneath .... but not enough to cause a problem.

Bear in mind, when using rivet nuts, lubricate the screws that will be installed. You do not want them seizing in the nut and trying to twist it out of the sheet metal. I will be tack welding the nuts on the bottom side when all the test fitting is done to prevent this. When installed properly they function quite well ... but if a screw seizes in them, and they turn in the sheet metal it can be a real pain getting the screw out.

[dataway]

Continued ......

Photo of the rivet nuts all installed.






Photo of the finger guard installed.




Testing fitting radiator/finger guard/shroud.

A note on the radiator insulators. I have yet to find ANY repop FOUR CORE insulators that fit properly. The best choice if you can find them are original insulators. The 3 core originals on cars with AC and auto trans had one on the right side that is a close fit. Anything you use except original four core insulators will have to be modified. It's not as simple as you might think, it's not just getting the insulators to fit the top seam of the radiator tanks ... the radiator has to be positioned the correctly in the finger guard or the shroud bolt holes will not line up with the holes in the finger guard, or will hold the shroud too far away from the radiator core.

Work slow and test fit ... the core should not be so far to the rear that the shroud holes will not line up with the finger guard ... and should not be so far back that it leaves a space between the shroud and the core. The shroud should not be more than about 1/8" away from the core or the fan will just pull air through that space rather than through the radiator. If the core is too far to the rear then the shroud will be against the radiator nicely, but the shroud will be held out too far to the rear and will not line up with the holes in the finger guard.

In most cases it appears to me that if you CENTER the radiator tanks in the insulator (front to back) by trimming the insulator, that everything will line up. By "center" I mean the same amount of insulator hanging down on both the front and the back of the radiator tank seam.

I'll try to expand more on this later.

[mrennie]

Very nice workmanship. You have some very useful skills!

[400 4spd.]

X2!!

[dataway]

What totally sucks is that I won't really know if this whole thread has any value until the body is on the frame and I can hook up the fenders. If it is all whacky ... then I'll ask the admin to delete this thread and I'll say "nevermind"

Installed the core support on the frame yesterday with the radiator and shroud in place. Had the wife holding it up while I tightened the frame mounts .... she points at the upper radiator hose touching the radiator inlet and says "just hook this thing up to there to hold it in place" .... which is a good sign, the hose and radiator seem to be in the right place

['ol Pinion head]

Has a LOT of value to those that think they have to order one of the Taiwan "one fits all" core supports. Also for all of us that dont have nice original, or have misplaced 4 core rubber insulators. There may come a day when I'm faced with modding a repro coresupport, but for what Pontiacs I'm restoring ('70-72's), am only restoring nice original coresupports.

As far as for a rotted out '68 core support selling for an exorbitant amt on eBay, I wouldn't believe the results of every auction on eBay. Comsiderable amt of games are being played there. In used parts circles, '68 & 69 V8 Pontiac A-body coresupports are easily the most common used core supports out there of all the very different '68-72 Pontiac A-body coresupports.

[dataway]

Up here in the North East .... they are few and very far between, and in horrible condition. I check places like Frank's pretty often and rarely see a 68 for sale, 69 and later yes, but the one year 68's no. The 68 parts car I stripped to get a lot of needed parts for my project had a lot of good parts ... and yet the core support was trashed ... they take a LOT of abuse from the salt up here. By the time I got a nice one shipped up here I'd have to be in the $600 range ... and still probably have to do welding and restoration work on it. So, while the repop is a total pain, since I have the tools and metal shop ... it's a viable alternative. Probably not the case for most people with 68's, they would have to find a used nice one .... which would probably be cheaper than paying a shop to do all the work I've done on my repop. A repop made sense in my case, probably wouldn't be the same for most people.