How to retrofit a late convertible hardtop
 

I will be submitting this to SoCalman as a sticky:
RETROFITTING A 1989 THRU 1996 CORVETTE CONVERTIBLE HARDTOP TO FIT THE 1986 THRU 1988 MODEL:

In March of 1989 production was started by the ASC Corporation of Southfield, Michigan on this beautiful 64 pound top. It was designed to be bolted on to the body after the folding soft top had been stored underneath the rear hatch lid.
The hardtop will bolt to the earlier C4 models but three things need to be changed:

1. With the help of a donor 1989 thru 1996 Corvette (either coupe or convertible) you will need to swap in the front latching system and the upper plastic trim piece that runs between them.

2. You will need a donor 1989 thru 1996 convertible to for its rear deck lid. You can remove the hardware from the later deck lid and swap things over but I find it easier to just swap in the entire piece.

3. The GM authorized hardtop has a built-in aquare roll bar that attaches behind the doors with the help of a dog-leg bracket that ties the frame of the car to the hardtop's roll bar. There is an aftermarket top that is made by Smoothline Industries but it does not incorporate the roll bar or its attachment points.
Since there is no place to attatch this dogleg brace to the earlier C4 body you will have to fabricate one. First remove the bolt that secures the shoulder belt to the stancion adjacent to your shoulder when you are seated. With the hardtop in place you will make a cardboard template in an L shape with 2 spots to be drilled inr the vertical portion of the L to be secured to the square roll bar. The horizontal portion of the L bracket will be drilled with a hole that will allow the shoulder belt to be reattached and secure the new bracket. The driver and passenger L brackets will then secure the frame to the hardtop and give your convertible a more solid feel.
Take this templates to your welder and have them fabricated out of heavy steel plate.
Installation can be done by 1 person but it is easier with 2. Lower the convertible top and the rear deck lid. Flip the sunvisors down. Set the hardtop onto the car and loosely bolt in the front upper windshield bolts, the rear 2 bolts that take the place of the soft top pins, and The brackets behind the doors. If your hardtop did not come with an installation tool then it is a good idea to purchase a ratcheting wrench (flat 8mm for the rear and the appropriate size Torx bit for the front). Once everything is lined up then snug the bolts down and enjoy the new quiet and rigidity of your cool weather cruiser.
Just be aware that you will lose easy access to the storage space behind the folded convertible top. Pretty much leaves enough luggage space for a skimpy nightie and a toothbrush for your partner. :)

Here are the stock side brackets:
http://im1.shutterfly.com/media/47b5...D720/ry%3D480/
The fabricated brackets installed:
http://im1.shutterfly.com/media/47b5...D720/ry%3D480/
Had to redrill as I did not measure correctly:
http://im1.shutterfly.com/media/47b6...D720/ry%3D480/
http://im1.shutterfly.com/media/47b6...D720/ry%3D480/
Lookin good!
http://im1.shutterfly.com/media/47b5...D720/ry%3D480/

I have heard that you can swap the B-pillars so you have the factory mounting points.

Oh, and do not forget to get the decklid liner (sits on top of the deck lid to add the "finished" look and cuts down glare), and the wiring for the rear defroster. I also recommend getting something to protect the decklid. The hardtop will grind the decklid, so either get a protector from the catalogs or some clear bra will do the trick.

Nice writeup Ron, kudos! :cheers:

http://i19.photobucket.com/albums/b1...MarinaShot.jpg

I don't know about the earlier models (I imagine that they are similar) but for later ragtops you can remove the folding top when the hardtop is installed. Since the torx bolts that hold the convertible top frame are more-or-less hidden, you have to remove the entire 3-bolt mounting plate, take off the ragtop frame, and then reinstall the mounting brackets to receive the hardtop mounting arms. I'm going to do that next winter -- the hardtop is on my car seasonally -- to reduce useless weight and open up a little more storage space.

Correctly retrofitting a pre-89 convertible
 

I aquired a factory original hardtop 5 0r six l years ago at a swap meet and had it painted to match my 1987 convertible. After that it sat in storage in my basement while I have been trying to figure out how to mount the top to the car.

I recently came across this posting and began to make plans on fabricating brackets. I removed my seats and pulled out some of the carpet around the shoulder harness attachement point. Upon close inspection I noted the attachment point is nothing more than a 5 sided (4 sides and an end) sheet metal box-type bracket. It is not really a sound structural attachment point for anything other than the shoulder harness.

The mounting of the brackets to the top of the shoulder harness mount is a novel approach that does provide a solution but was not designed for such use and therefore is not really a good attachment point. In the event of an accident and if litigation would follow there could be case for liability arising from modifications to the seat belt attachment. Civil Liablity Lawyers specialize in capitilizing on these kind of cases where someone makes a modification that is not "professionally designed and engineered"

I continued my internet quest and finally saw a photo that showed the correct B-pillar pivot arm bracket for mounting the soft-top and hardtop for 89-96 vettes.

My recommendation is persons interested in retro-fitting a pre-1989 convertbile vette to contact corvette salvage yards and obtain the correct B-pillar brackets from an 89 to 96. By surfing I was able to find a salvage yard in St Charles, MO and they had the correct factory parts on my doorstep within 24 hours. Then it was a simple matter of switching out the brackets and now I have my 89-96 optional factory hardtop correctly fitted and mounted to my 1987. I had already obtained the correct factory windshield header retro-fit kit from a corvette parts retailer. The hardtop looks great on the car. It is correctly designed and engineered and I am proud to show my car with the correct factory parts assembled. If someone needs additional information. I would be happy to share further information, including pics (I took lots of pictures showing the old brackets and the correct factory brackets) of how the brackets mount on the car.

1988 convertible with a 1993 convertible hardtop
 

So what exactly do I need for this top to fit? Is it just the correct B-Pillar pivot arm brackets from a 1989-1996 convertible and the windshield header kit?

There is a sticky here on this procedure that I wrote up. I really do not see any place on the 86/87/88 for the stock B pillar bracket to bolt to the body. I respectively state that the previous post stating that they will fit is not accurate. I would like to see the pics if you accomplished this.
I bought my hardtop from a vendor while I was at Bloomington Gold with my previously owned 87 convertible. I was able to drive he car to the vendor's space and Gordon Killebrew was there and assisted me with the process. The vendor did not have the later header pieces for me at that time so we did not install the hardtop that day. Gordon said nothing about using the stock B pillar brackets but to simply bolt it on using the front and rear mounting hardware from a 89-96 C4. I learned about making the custom B pillar brackets from someone else here on the Forum.
Litigation from an accident that might never happen? Geez - I survived 2 wars, been shot at, stabbed and mortared. Also survived being married to a hot tempered Irish gal along with raising 2 boys and 2 girls through their teens. I will take my chances brother.

B pillar Attachment
 

Does anyone have pictures of the B pillar mounting points for the hardtop brackets? Also, are the mounting points part of the soft top mounting bracket? Thanks for any help.

B-Pillar Mounting on early C4 for adding a later year hardtop
 

I added an 89 hardtop to my 87 convertible a number of years ago. To do so requires swapping out the B-pillar bolt on brackets with later model (89 - 96). I found mine through the internet at a corvette salvage dealer. It will take a lot of time to track down all the correct parts but it will be worth it, if the aftermarket hard top was replicated to bolt on as originally designed back in the day. I have uploaded some information. Let me know if this helps. JKH

Thanks for the picture. It's much appreciated and clearly shows that the convertible bracket for the 89 and up is much different than the 88 and older. I just ordered the brackets from someone on EBay, so shouldn't be long before I can fully bolt up the hardtop. I've already sourced and installed the windshield frame brackets as well as the deck lid brackets.

Hello will the 1987 soft top front latches latch to the 89- 96 front and rear latches? Or am I stuck swapping out the front and rear latches when I want to use my soft top. I want to be able to use both the soft and hard top whenever I want to. Any help is greatly appreciated . Thanks in advance!!

The header brackets will work with the older convertible top latches, as will the rear deck lid latches work with the top's pins.

Corvette Hardtop
 

Do you have the name of the place you ordered your retro-kit from? I’m experiencing a slight problem with an OEM hardtop that I’m trying to put on my convertible 89. It appear that the hardtop has the correct brackets that cinch to the windshield but my bolts on the actual windshield are located a little wider out than the bracket on the hardtop. I’m thinking I can probably slot both bolt holes on the hardtop’s brackets and slide them over so the bolts will go on but I want to check and make sure that’s the right move or is it something I’m missing. The brackets are of by just below 3/8 inch. Any help or knowledge you can provide would be greatly appreciated.

Need help
 

.... i have a 87 i am trying to do the same i can not find parts if can help pls

Where are you located? I see there is an 89 convertible in one of the Southern California wrecking yards. You could try posting a WTB ad in the forsale section here and might find one of the members that parts these out.

Which wrecking yard?

Sun Valley LKQ Pick your parts. I found one in there back in November and was able to get a bunch of the convertible weather stripping frame pieces for mine. There's another one in there now. The Sun Valley one is the worst of them though. They overcharge on everything.

I know this is 9 months later but...
 

Yep. It's getting harder to find parts to retrofit these hardtops. I will say getting the oarts are easier than trying to modify everything to get it to work.
https://cimg6.ibsrv.net/gimg/www.cor...5aadcb3387.jpg
The mounting bracket sits on a lip of the B pillar.
https://cimg9.ibsrv.net/gimg/www.cor...15c65237ec.jpg
Another angle of the B pillar with supplied bracket for hardtop.
https://cimg3.ibsrv.net/gimg/www.cor...ab32080f98.jpg
Front of hardtop. Center hole is where bolt holds top.
https://cimg5.ibsrv.net/gimg/www.cor...10f2abc072.jpg
86-88 front bracket. Needs a hole drilled to attach from inside of car.
https://cimg0.ibsrv.net/gimg/www.cor...530557882a.jpg
Top not attached but the pin is secured by the latches in the deck lid. A nut and washer affixes it to deck lid.
https://cimg2.ibsrv.net/gimg/www.cor...1b6ab89209.jpg
B pillar without bracket attached
https://cimg1.ibsrv.net/gimg/www.cor...78a972a67e.jpg
B pillar that comes with cars from 86-88. You will have to modify a lot to get it to fit.
I bought a B pillar from a recycler in Utah. That cat stuck me up for over $200 for just one side. I didn't need the passenger side because the previous owner(s) put the 89-96 pillar on. I bought the rear cover from Mirrock. Wrong color but I'm going to paint the whole car because of orange peel anyhow. I was going to buy the front windshield brackets but I believe you can drill out a hole and be able to attach the single bolt on each side. I left some pics. Hope this helps.

A detailed look at the B-pillar pivot mounts
 

I had some confusion on the B-pillar brackets and couldn't find much information or pictures aside from what housepumpinpc and JKH posted. Finally bit the bullet and ordered them, here's how it went. I have a 1988 convertible, found a hardtop locally after months of searching. Now I'm in the process of retrofitting all the hardware. Wanted to post along the way so more information is available for us in the future.
https://cimg5.ibsrv.net/gimg/www.cor...7908bfa3e5.jpg
1996 bracket laid over the 1988. Its a direct fit bolt-on if you swap the later model brackets to a 1986-1988 convertible. No modification required.
https://cimg3.ibsrv.net/gimg/www.cor...66a55f121e.jpg
Top (1988) and bottom (1996) pivot mount brackets side by side.
https://cimg6.ibsrv.net/gimg/www.cor...1a52360920.jpg
Passenger side with the bracket removed. Theres 3 13mm nuts and 2 T40 screws with a 13mm nut on the end, one for each pivot arm. One of the 13mm nuts (rear) holds the tensioner cable for the soft top. It should be sandwiched between the bracket and the nut, don't put it between the bracket and the bolt. That may cause fitment issues.
https://cimg7.ibsrv.net/gimg/www.cor...f993484771.jpg
This carpet piece has to be removed before accessing any of the bolts. Be gentle, it may be brittle with age.
https://cimg9.ibsrv.net/gimg/www.cor...da43aef558.jpg
Here is the 1996 bracket bolted in. Fits perfect to the 1988 hardware, but the old carpet won't fit anymore. You can cut holes for the hardtop dogleg brackets into the carpet, but i preferred to leave it off.
https://cimg0.ibsrv.net/gimg/www.cor...a86ad9ff49.jpg
https://cimg1.ibsrv.net/gimg/www.cor...e460b86c20.jpg
Driver side has this support piece over the pivot arm bracket. 2 larger bolts (left) were easily removed, then the 2 13mm nuts on the pivot bracket to unbolt it. This piece will be in the way of the lower bolt on the dogleg bracket, so you won't be able to reinstall it. I left it out.
https://cimg2.ibsrv.net/gimg/www.cor...e4d11d3569.jpg
Heres the 1996 bracket installed.
https://cimg3.ibsrv.net/gimg/www.cor...c1030ebf00.jpg
Hardtop dogleg bracket fits right on.
https://cimg5.ibsrv.net/gimg/www.cor...2b31479edd.jpg
The trim over the driver side. Theres not much difference with the carpet out visually. I'd leave it this way to keep the hardware easily accessible.

I ordered these parts from Mirrock Corvette. They have an Ebay and website, lots of secondhand parts available if you can't find it on any of the retailers.