installing 78 c3 dash
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Go read this first... and then when your done you'll think it sounds easy... it's not.
http://repairs.willcoxcorvette.com/w...stallation.pdf
There are a few tricks to doing the 1978-1982 dash pads.
1) Fitting the center dash bezel can be difficult. We have one here that we cut all the middle out of.. and we use it to mark the holes. However, we don't drill the holes for the center dash bezel when we install, we use an awe and heat it with a mini torch and then burn them in place. You have to be careful not to push the awe in to far because it'll come out the face surface of the pad.
2) Pre-fit the wiper switch and burn the hole for it as well. If you pre-fit the wiper switch you'll be leaps and bounds ahead of the bus because if you try to do this with the dash pad installed it's kind of hard. The wiper switch has to clip in and then has one single screw that holds it in place, making sure you get this in the right place is critical and way easier before the dash pad is installed.
3) The lower duct connections.. they are a bit tricky and if you do break or have a broken ear you can use plastic fusion (or plastic weld) to fix them. Pre-fit these before you put the dash pad in as well.
4) We do the speedo tach housing the same way.. we use the awe (remember a short one) to burn the holes in the pad. Test fit it as well.
5) Remove the steering column, there are instructions on our tech site... it makes this job way easier.
6) While you don't have to install new speakers before installing a new dash pad, it's way easier if you do this before putting the pad in place. If you don't you'll need to fabricate a tool to screw the hex bolts in place... doing it on your lap is again... way easier.
7) Never trust the pre-marked holes for the striker on the glove box... If you drill them wrong your door will not shut all the way. How do you know where to drill them. You'll have to look at your old pad and make a guess. But... history has shown that if we drill the holes inward about 1/8" from the marks they will be in the correct place. And most important... don't ever think the glove box doors fit worth a hoot when the cars were new... they didn't. The door has more curve to it at the top right than the dash pad and this was the way the cars were when new. (see the bottom picture)
I've copied some notes from the facebook page below...
Dash Vent Deflectors (outer) can be a trick to install too. In this installation one of the duct retainers was broken. One tab was cracked off and the other side was warped and would not hold the new deflector properly. The fix… Again, plastic weld or plastic fusion can be used to repair the broken tab. (In our case we had a good used one in stock). The fix if the vent holders are bent or warped is to heat them with a heat gun until they become pliable and then with a cold wet rag squeeze them inward. When the cold rag hits the hot plastic it will hold the new form. It may take a few attempts to get it right and our advice is to use a blow drier vs. the heat gun at home.
There are some other tips on our facebook page, but I'm moving all of this to our regular tech site soon. https://www.facebook.com/pg/WillcoxCorvette/photos/?tab=album&album_id=10152574879282925
Willcox
My original 78 shown below.
http://repairs.willcoxcorvette.com/w...stallation.pdf
There are a few tricks to doing the 1978-1982 dash pads.
1) Fitting the center dash bezel can be difficult. We have one here that we cut all the middle out of.. and we use it to mark the holes. However, we don't drill the holes for the center dash bezel when we install, we use an awe and heat it with a mini torch and then burn them in place. You have to be careful not to push the awe in to far because it'll come out the face surface of the pad.
2) Pre-fit the wiper switch and burn the hole for it as well. If you pre-fit the wiper switch you'll be leaps and bounds ahead of the bus because if you try to do this with the dash pad installed it's kind of hard. The wiper switch has to clip in and then has one single screw that holds it in place, making sure you get this in the right place is critical and way easier before the dash pad is installed.
3) The lower duct connections.. they are a bit tricky and if you do break or have a broken ear you can use plastic fusion (or plastic weld) to fix them. Pre-fit these before you put the dash pad in as well.
4) We do the speedo tach housing the same way.. we use the awe (remember a short one) to burn the holes in the pad. Test fit it as well.
5) Remove the steering column, there are instructions on our tech site... it makes this job way easier.
6) While you don't have to install new speakers before installing a new dash pad, it's way easier if you do this before putting the pad in place. If you don't you'll need to fabricate a tool to screw the hex bolts in place... doing it on your lap is again... way easier.
7) Never trust the pre-marked holes for the striker on the glove box... If you drill them wrong your door will not shut all the way. How do you know where to drill them. You'll have to look at your old pad and make a guess. But... history has shown that if we drill the holes inward about 1/8" from the marks they will be in the correct place. And most important... don't ever think the glove box doors fit worth a hoot when the cars were new... they didn't. The door has more curve to it at the top right than the dash pad and this was the way the cars were when new. (see the bottom picture)
I've copied some notes from the facebook page below...
Dash Vent Deflectors (outer) can be a trick to install too. In this installation one of the duct retainers was broken. One tab was cracked off and the other side was warped and would not hold the new deflector properly. The fix… Again, plastic weld or plastic fusion can be used to repair the broken tab. (In our case we had a good used one in stock). The fix if the vent holders are bent or warped is to heat them with a heat gun until they become pliable and then with a cold wet rag squeeze them inward. When the cold rag hits the hot plastic it will hold the new form. It may take a few attempts to get it right and our advice is to use a blow drier vs. the heat gun at home.
There are some other tips on our facebook page, but I'm moving all of this to our regular tech site soon. https://www.facebook.com/pg/WillcoxCorvette/photos/?tab=album&album_id=10152574879282925
Willcox
My original 78 shown below.
Last edited by Willcox Corvette; Mar 12, 2018 at 09:46 PM.
