C3 4ME

I have learned from here that 79 L-82's with A/C and no front pace car spoiler got a an extension to the standard air dam. I was as Zip Corvette's open house today and they showed me part # ET-534 which their catalog lists as a spoiler extension for L-48 with heavy duty cooling, but I'm wondering if they listed it wrong. I looks in the pic correct for an L-82 from what I know. http://www.zip-corvette.com/79-l48-s...ct-media-modal Can anyone confirm this? Unfortunately, all they had was a catalog pic to show me, they didn't have one in stock to check out.

LS4 PILOT

I owned a blk.79 l82 with M21 plus AC . Non spoiler car. It was about I year old when I bought it . 100 % stock. I have never heard of a L48 having the extra extension added to plastic chin spoiler from factory.

So few people even know about this item, it is most likely a mistake , should be L82 . AIM would confirm. These places are often confused when it comes to these unique rare parts .

My 79 car...It DID have the plastic spoiler ....plus the deeper rubber like extension added riveted to the hard plastic chin damn.

A very simular extension of the exact material was used on 73-74 454 AC cars. It is on my present 74 car. Makes a diff.....for sure on cooling the BB. It was first used on these cars.

I ve never seen any repop material that was the same , it was some strange tuff thick stuff simular to the A arm dust shields .....about five times th thickness maybe.

The shape looks correct. The original material is flat and not smooth or slick.

There are two tuff steel strips that the extension rivet to , these are behind the plastic air dam.

The extension is riveted to the plastic dam. These rivets are kinda unique .
Seems everything GM did was spec hard to find. These rivets had a huge head on them ...about dia. of a penny .....i don't know where you d ever find them.

One thing I noticed on some very bad reproductions a couple guys did , the material is kinda critical. Theirs was too soft . ...they need to hold their shape to keep the scoop effect .

You need to check out an original extension , then you can understand what your actually looking for. One of these things where a picture is not going to tell you the material feel .

C3 4ME

Damn, wish I had thought to check out the other 79 L-82 at the open house today. It had the extension on it, and i took pics of it, but didn't know to check out the material. It definitely makes sense that it would have to be fairly rigid so doesn't deform at speed.

LS4 PILOT

Bingo.....you understand

There was a guy in Michigan years ago that made a couple batches of poor repo ps . Junk....and people paid a lot during the corvette hey day.

You best bet , is to find a junk car that some how it survived. The extension material is nearly indestructible. You could tear the whole Deal off , but not tear the extension.

The original factory plastic chin s were also very tuff and thicker than the over the counter factory pieces issued years latter ....80's up.....ones that are NOS ......I ve not seen a real NOS thick one in 35 years.
Are not as thick heavy plastic as the ones cars came with in the 70's .
The extra extension is heavy , with backing brackets ......it stress a latter GM replacement spoiler . ....tho it will fit .

I think original factory 70's A arm dust shield is the correct stuff Or at least the texture is very similar to the touch.The original extension is very rigid , very tuff to bend 1/4 " thick I'd say.Concrete will scuff it , but not tear it .......the plastic spoiler will give away first ....LOL.

hunt4cleanair

The part OEM description is radiator grille lower extension and was base equipment when RPO V01 (heavy-duty radiator) or L82 engine (1979) were equipped. So the catch here is V01 in either 78 or 79 that was base equipment when the tow package (RPO ZN1) was ordered. This is probably where Zip incorporated the L48 reference. L48s could be ordered with RPO ZN1.

Vendors abbreviate descriptions to accommodate data field descriptions and no telling if there is supervision to validate data field descriptions with OEM descriptions.

Having said all that, I suspect build sheets would confirm original equipment configuration because with RPO V01, it would call out the grille extension. Equally, L82 in 79 would also call out the grille extension and its associated RPO. By doing some basic comparison analysis, one can identify various equipment associations. I'll look through my inventory and see if I have a 78-79 V01 with grille extension or 79 with L82.

BKarol

The one in the link looks like the original for the L82. If you want more air then it would be a good purchase but I have not heard of anyone producing these. At one time Willcox mentioned producing them. There are posts here of guys making their own. I could not find a rigid material so used something soft to see what happens. It attached to the spoiler and hung down another 2 inches and did result in lower temps on the highway. I cant tell if it moves around being soft because I am driving.

Thanks for the pic KapsSA:

C3 4ME

I knew I had seen a pic here, and was pretty sure it was KapSA"s car. I know he has a couple ultra low mile very original cars. I may ask Zip if they'd order one in so I can actually see it and make a decision from there. My car has always run hotter than I like at interstate speeds (an indicated 220 on the factory guage) and it cools down when you slow down, so it's always been my belief that it's not getting enough air flow at high speed. It will idle all day an not heat up. Yes, my radiator seals are there and in good shape, the radiator itself is fine, and I've even made sure to run a lower radiator hose with a spring in it.

mark79,80

I also have a 1979 L82 and this spoiler extension was missing. Years ago I ordered one from DrRebuild. In his 2008 on line catalog, it is listed on page 199 as part 1274738. You will also need two metal strips behind the factory extension to hold pop rivets that are inserted thru the spoiler extension. They are listed as part no. 1274742. I had some galvanized metal strips used to hold duct work in commercial buildings which worked fine.

C3 4ME

Do you remember if when you added the spoiler extension it made a difference in the operating temp on your car?

mark79,80

I don't, but we have much fewer hot days here, than in your area.

hunt4cleanair

I recognize the discussion has moved onto operational functionality...what it needs to be all about.

So I looked at my buildsheet inventory and it confirms my initial thoughts. I feel like Rush here with my data-driven speculations.

In 1979, L48s with the RPO VN1 trailer package and C60, were equipped with the heavy-duty radiator (RPO V01) and the RPO D80 extension (lower grille extension). But L82s with C60 were equipped with the same D80 extension which means the part number would be the same for both power team configurations. The L48 included M38 while L82 was with M21, so transmissions make a difference here with M38 requiring more heat dissipation. Fluid lines for M38 run through the radiator. Both radiators were heavy-duty and called out the broadcast code ML in 1979.

In contrast in 1978, L48s with RPO VN1, were not shipped with D80 extension but did include RPO V01. Engineers figured something out during 1978 in regards to powerteam configuration and their cooling requirements.

That is what I like about the study of buildsheets...it is definitive!

red topless gator

I also had a 79 L82 4 speed with A/C that had the original rubber bottom air dam, but it was BUTT UGLY. Replaced it with a regular air dam and never noticed the diff.

Zip Corvettes

They could have been on a L48 with HD cooling. They first surfaced on the 73-74 BB air cars, and then it was part of HD cooling.The 79 L-82 A/C had it stock since they came with HD cooling. The early ones did not have the split in the front, I believe that came about in 78. These were a thick rubber and they rivet to the stock plastic air dam with two metal reinforcements behind. They can be used on any year car from 68-79 to help with cooling. I personally like the look of them on a mid 70's car, they give it a little more aggressive look from the front. We do stock them but they are not in stock. We have had them on order for a several weeks right now.

C3 4ME

Give Justin McNeer a pat on the back. He found this on Saturday when I was in the showroom. I had looked for it before in your catalog and hadn't found it.

wendellp601

If you purchased one of these, can you collect some before & after temperatures when you install it?

I found my entire plastic chin spoiler missing from my '77 and ordered a new one along with the rubber extension. I installed them at the same time and saw a 20° to 30°F reduction.

rcread

I put one on my '71.

jano344

When you added this.....did you use any type of metal retainer across the back of the spoiler extension?

C3 4ME

If that question was directed at me, I never wound up putting one on. Instead, I now have a repro front pace car spoiler mounted on mine. It did make a difference in operating temps, but not as much as I'd like.