Choosing a radiator to hood seal for '70-'72 454

[Mark E.]

I'm choosing a hood seal for the top of the new core support on my '70 LS5.

Looking at the image below from docrebuild.com, That site says C is the original style seal for 1970, D for 1971, E for 1972.

The gap between the core support and hood ranges from about 3/4" towards the edges of the hood to about 2" at the center.

This means seal "C" (original style for '70) would leave a gap above the hood towards the center. And it looks like the seals for '71 and '72 (D and E) were changed/improved to seal across the width of the hood.

Would someone provide feedback on these thoughts:

- I believe the core support/hood configuration is the same for 70-72, so seals C, D, E would fit the same across these years.

- D and E fit against the hood across their length, while C does not

- Compared to D, it looks like E was lengthened to extend across the entire width of the hood

- Conclusion: C would provide the original look for my car, while E may perform the best.

Capture.JPG

[Joe L.]

Re: Choosing a radiator to hood seal for '70-'72 454

- Conclusion: C would provide the original look for my car, while E may perform the best.

[ATTACH=CONFIG]69802[/ATTACH]

Mark-------


This is EXACTLY the correct conclusion.

[Paul O.]

Re: Choosing a radiator to hood seal for '70-'72 454

Photo of an original 1970 LS5

[Mark E.]

Re: Choosing a radiator to hood seal for '70-'72 454

Thanks Paul. It looks like the outer 5" or so of each end of the seal is compressed where it contacts the hood. The center of seal isn't compressed so it's probably not making contact. Plus the seal does not extend across the full width of the hood.

Do you think this seal makes any difference?

[Mark E.]

Re: Choosing a radiator to hood seal for '70-'72 454

How is this seal attached to the core support?

I thought it was attached using weatherstrip adhesive, but docrebuild.com says two metal push pins are used, which they sell.

My new core support doesn't have holes on the top for fasteners, nor do I recall seeing pins on other cars.

[Terry M.]

Re: Choosing a radiator to hood seal for '70-'72 454

How is this seal attached to the core support?

I thought it was attached using weatherstrip adhesive, but docrebuild.com says two metal push pins are used, which they sell.

My new core support doesn't have holes on the top for fasteners, nor do I recall seeing pins on other cars.

1970 attaches using a self-adhesive attached to the foam strip. You peal off a paper cover and stick the adhesive to the core support. 1971 & 1972 used the plastic push pins Dr. Rebuild describes.

[Paul O.]

Re: Choosing a radiator to hood seal for '70-'72 454

As Terry stated only self-adhesive secure the seal to the support no pins were used. Also item "C" is the one typically seen for your car. Sorry I did not add that earlier but have to many jobs going on right now.

[Mark E.]

Re: Choosing a radiator to hood seal for '70-'72 454

1970 attaches using a self-adhesive attached to the foam strip. You peal off a paper cover and stick the adhesive to the core support. 1971 & 1972 used the plastic push pins Dr. Rebuild describes.

Dr. Rebuild says the push pins are steel. Is that correct?

Where are the holes for these pins?

[Joe L.]

Re: Choosing a radiator to hood seal for '70-'72 454

Dr. Rebuild says the push pins are steel. Is that correct?

Where are the holes for these pins?

Mark------


The push pins are just as the Doc describes; they are of steel material. Contemporary fasteners of this type are almost always plastic but that's not how it was back in the early 70's. Some of the reproductions I've seen are plastic, though.

There are plenty of holes for the push-pins as shown below. The push pins were of GM #3966532.


DSCN3282.jpg

[Mark E.]

Re: Choosing a radiator to hood seal for '70-'72 454

Mark------
The push pins are just as the Doc describes; they are of steel material. Contemporary fasteners of this type are almost always plastic but that's not how it was back in the early 70's. Some of the reproductions I've seen are plastic, though.

There are plenty of holes for the push-pins as shown below. The push pins were of GM #3966532.

Thanks Joe. The Coffman reproduction core support on my '70 doesn't have those holes. Maybe only '71-'72 have those holes since they use the push pins?

It looks like your car needs a seal too.

[Joe L.]

Re: Choosing a radiator to hood seal for '70-'72 454

Thanks Joe. The Coffman reproduction core support on my '70 doesn't have those holes. Maybe only '71-'72 have those holes since they use the push pins?

It looks like your car needs a seal too.

Mark------


The radiator supports (and their part numbers) changed for late 1969. I believe the holes were to have been added at that time. However, I don't think this actually happened for some unknown reason. My very late 1969 small block had the later style support but did not have the holes for the pushpins. So, my car had the "3 piece" style seal with each piece retained by PSA. Just when the holes for the push pins were added, I do not know. I don't think the part numbers changed when the holes were finally added.

Yes, I need to install the seal and I have it. I'm going to use the "E" style seal as it's the most efficient.

[Terry M.]

Re: Choosing a radiator to hood seal for '70-'72 454

I'm choosing a hood seal for the top of the new core support on my '70 LS5.

Looking at the image below from docrebuild.com, That site says C is the original style seal for 1970, D for 1971, E for 1972.

The gap between the core support and hood ranges from about 3/4" towards the edges of the hood to about 2" at the center.

This means seal "C" (original style for '70) would leave a gap above the hood towards the center. And it looks like the seals for '71 and '72 (D and E) were changed/improved to seal across the width of the hood.

Would someone provide feedback on these thoughts:

- I believe the core support/hood configuration is the same for 70-72, so seals C, D, E would fit the same across these years.

- D and E fit against the hood across their length, while C does not

- Compared to D, it looks like E was lengthened to extend across the entire width of the hood

- Conclusion: C would provide the original look for my car, while E may perform the best.

[ATTACH=CONFIG]69802[/ATTACH]

Mark

I was looking for something else and found this picture of a late 1970 LS5 in my files. I can't tell you how late, not can I tell you if this core support to hood foam is typical, but this is one unrestored example for you.

late%201970%20LS5_zpsdt4htxuo.jpg

[Joe L.]

Re: Choosing a radiator to hood seal for '70-'72 454

Mark

I was looking for something else and found this picture of a late 1970 LS5 in my files. I can't tell you how late, not can I tell you if this core support to hood foam is typical, but this is one unrestored example for you.

[ATTACH=CONFIG]69861[/ATTACH]

Terry------


That's the 3 piece configuration I referred to earlier. It's essentially the same as my original late 1969 small block configuration. The only difference is that on mine the space between the pieces is a little bit greater.

[Terry M.]

Re: Choosing a radiator to hood seal for '70-'72 454

Terry------


That's the 3 piece configuration I referred to earlier. It's essentially the same as my original late 1969 small block configuration. The only difference is that on mine the space between the pieces is a little bit greater.

The 1970 configuration I am used to seeing has only a single long center piece. Like the Doctor's drawing for part C. I guess Mark has some options.

[Mark E.]

Re: Choosing a radiator to hood seal for '70-'72 454

Thanks Terry and Joe.

Terry- You and the team did a great job leading the Judging School in Grapevine. And I'm looking forward to the revised 70-72 JG that's in the works.