1999PewterCorvette

Just got my 78 pace car two days ago.
My t-tops say dot15 M1131 on them and have a little sticker that says
Warning- This t-top locked and serial numbered.
This pace car is totally original (39000) miles.
A friend told me that these t-tops are very rare on a pace car and
very expensive. Why are they so rare and expensive??.
Are these warning stickers supposed to be removed.??
Were there only a few made?
sorry guys im new to the C3 world.

Rob

sperkins

Your friend is correct. Here is what you have.



Dot15 = The US Department of Transportation number.

M1131 = Laminated, blue tint, came on factory corvette's from 1978-1981. These tops are very rare and expensive.

It is rare because it is Laminated and not Tempered.

Laminated - Like a windshield, has a thin peice of rubber sandwiched between two thin panels of glass. Problems were that they were very fragile. Normally they do not break, but have hairline cracks. Very low production.

Tempered - Solid glass panel which is very strong. It shatters into a thousand little peices like a door glass when it breaks.

I would not remove ANY labels on them at all.

1999PewterCorvette

great thanks for the reply.
but they dont look blue.
They are mirrored.
Are there mirrored M1131's and blue M1131's???

1999PewterCorvette

they do say laminated-- i remember that.
i know they had dot15 m1131 on them.
I dont remember seeing the word blue on them--but in the morning i will have to check.

sperkins

I'm pretty sure the M1131 was only offered in the blue tint. Check closely because they may just look to be mirrored. As far as I know, the code for 'Mirrored' glass is M95C.

2TONE82

What you have are LOF (Libby-Owens-Ford; the manufacturer) factory tops. They were an option from 1978 - 1982.
All the glass in an original Corvette will be LOF glass. It didn't take crooks long to figure out that the tops were interchangeable between the years. Replacement t-tops/glass was made by PPG.

I do not have the article with me but I recall the code AS3 (under the word "Safety in the photo above) is the T-Top Glass panel. AS1, AS2 were used for side, back, etc.

But most important, the glass is also date coded. It is hard to see in the picture above but the letters under the word "Float" equal a year/month. The date for both tops should be the same. Don't be surprised if the year is off - my tops were made in 1981 but the car was produced in Feb 1982 so the date codes matches up. You may find instances were some of the glass is off by a couple of months - this I was told had to do with manufacturer problems.

If you have one side glass that is PPG and the others are LOF suspect a break-in or accident. Front replacement glass on cars 20+ years old is common and no big deal...IMHO.

As for the warning sticker - this is a new one on me. Suspect the tops may have been etched with the VIN by a previous owner; a theft deterrent measure. They still make locks for the tops as well. I think the sticker is an aftermarket piece.

FWIW, a good set of tops will go for several hundred $$. I have a spare set for my '82; surprisingly the dates match the ones on the car.

1999PewterCorvette

Well, I just checked them.
They do say Blue LOF AS-3.
So I guess they are the real deal-- They even have the original warning stickers on them (pretty cool).
So, how expensive are these?? Do people really care about a car optioned with these???

Rob

sperkins

Good to hear. I felt pretty confident they were genuine. Hang on to those suckers. As far as what they are worth? You're not going to seel them anyway, so I guess it really doesn't matter unless you get some clown to offer you a ton of money. If you ever sell the car, you can use them as a bargaining tool.

Easy Mike

All Pace Cars had the glass tops. Post a picture of the warning label. If memory serves, the label is not stock and was probably added by a previous owner as a potential theft deterrent.

1999PewterCorvette

If EVERY pace car had these tops-- then why are they so rare?. Right there youre talking 6502 of these t-tops plus the ones that chose the option out of the other 34,000 corvettes that year. Werent they also made for other years?. To me several to many thousands of these does not seem rare to me.
When I look up 78 corvette specs, they list 900 or so cars out of the total 34000 built had removable glass panels. Are these the panels they are talking about?? If so, then it couldnt be on every pace car.
heres the link of the specs i found.

http://www.corvettes-for-sale.com/specs/78.htm

Rob

2TONE82

I think the 900 or so cars were above and beyond the pace cars - never seen a pace car with solid tops so the number of cars with glass tops includes the 6,502 Pace Cars plus the 972 "other cars" for a total of 7,474 in 1978 alone...rare, no. Fast forward to 2006 - how many cars are still on the road with glass tops - anybody's guess but if I'm selling my '82 it is very rare!

Here are some more numbers; ref the Corvette Black Book Year, Car Production and Glass Tops.

1979 53,807 14,480
1980 40,614 19,695
1981 40,606 29,095
1982 25,407 14,763

SLine78

Rob,

It was not until late 78 that a non-pace car owner could order the glass tops. The became an official option in 79. Of the colors the glass tops were offerd in, the LOF blue ones had the fewest produced. Given how easily they can become damaged and the fact that replacements used PPG glass, a set of orignal LOF blue tops after almost 30 years, creates a sellers market for them.

I am in the market for a pair for my 78, since on one trip, my orginal passenger side fiberglass t-top, was not latched properly, and as I was accelerating on the freeway entrance ramp, it caught some air and lifted off the car and went sailing like a frisbee. It landed on the corner by the pin, so that part of the stainless rolled under. It will still latch onto the car, but in addition the bent stainless, there are of course some scratches on the top where it came to rest. So now I want to replace the orginals with some glass ones, but they are so fragile, I worry about them getting damaged in shipping.

gliot1

I have a Pace with M1131s which I have just had to replace. The warning label is not stock. What I learned about these may help you. An original M1131 in good condition is worth good money. They were blue tint and can very in tint greatly; they fade quickly and don't hold heat out very well. Finding a pair of matched color is difficult. GM only produced those one year and moved to LOF glass. The problem with M1131s is that there are 1/16" laminated glass. What these means are they are delicate. I had mine in back strapped down and when I took them out they had a cracks in them. I had been doing this for a few years with no problem. I bought new LOf tops to replace them and the T-top restorer said they are extremely delicate and when I asked why they might have broke, he said there is no real answer. He said they are just that delicate becasue they are laminated and has seen them crack just driving. GM moved to LOF tempered glass which is thicker, stronger and much more difficult to break. I thought I just needed one which was $600 but when he checked the second one he found it was cracked; a pair would have been $1200. He could have sold me a new pair but made no guarantee and claimed these could break a week later. He said they are delicate. I figred I would never be judged a BG or NCRS level, so I chose to go with tops I could feel safe to drive around with. The LOF tops were $800 for a pair. Even with my tops cracked it appears I will still fetch about $250 for them. the bottom line is be careful with them and if you are showing and driving you may want to only use those tops for top end shows and buy LOF tops as well.

swtato

rare because you cannot buy blue m1131's any more. Then you also have to find one that matches if just replacing one top. Over time these can fade from blue, to light blue, to almost a smoke color.

1999PewterCorvette

wow--thanks guys for the replies.
I guess I better be very careful with them. Like mentioned above, it might be worthwhle to pick up a pair of cheap t-tops to use and save the originals for car shows, judging, etc.

Rob

Easy Mike

Didn't think so. Thanks for the info.

Red 69

Thanks for this interesting information about the tinted t-tops. The red 79 I bought a few months ago came with these exact same tops. I thought the blue tint was different, but now I have a greater appreciation for what they are. Thanks for the education!

jpkemp

You can't buy them new at the dealer, but you can still buy them from various ttop vendors. For a drivers side deep blue, get ready tp pay in excess of $1200+ plus shipping. Drivers side are the rarest, passenger side blues can be had for a little less because there are more of them around. To find a matching date code, new blue pair, good luck and get ready to shell out big bucks. Swtato is correct about the fading, so if you break one, matching it up is very tough. Check swap meets and ebay, occasionally you'll get lucky