I had that measurement from the rear of the door on a chrome bumper car but I don't think it was right as the numbers didn't seem to add up. It was 53 & 3/8 inches from the door opening to the back of the ducktail

and on my car from the door opening to the flange for the rubber bumper was 47 & 3/4 inches (although due to the curving of the quarter panel I couldn't make a really precise measurement) which meant I should have a little over five inches from the duck tail to the cut line which would have the ACI rear clip too narrow at the quarter panels to match the rear of the 79. Doorgunner shows 12 inches for the clip to be attached

and this conversion on a bubble back like mine appears to be around the five + inch mark but again, that made the ACI clip too narrow to match the rear of my 79 (the rear clip is widest at the front and narrows towards the ducktail).


I made a paper template of the upper deck at the bumper flange on my 79 and marked the width at that point. I placed the paper template on the ACI rear clip and moved it back and forth until the width on the template matched the width on the ACI rear clip and that place was where the remaining black line is on the ACI rear clip in the picture above. From that position to the ducktail is, if I remember correctly, 8 & 5/8 inches. At the 12 inch mark on the ACI rear clip it is too wide to match to the rear end of the 79 at the flanges where the rubber bumper bolted on. So, I wasn't able to make sense of the measurements I had hence I decided to go to the "cut it not enough and gradually trim till it fits" route.

 

In going through Doorgunner's thread again,if I've got it right, it appears that after he took the picture above he cut another 4" off the black rear of his 69 from where the rubber bumper would have mated to the rear clip. If I were to add another four inches to the aprox 8 & 5/8 of where I thought the ideal cut would be on my 70-73 ACI rear clip we'd be in about the same place though I still can't reconcile that with the picture of the 69 rear clip on the bubble back corvette I posted in the picture above which appears to be more around the 5 or 6 inch length.

 

Hi P,
I see what you mean.

"would have the ACI rear clip too narrow at the quarter panels to match the rear of the 79."

Really can only commiserate. No experience, so no advice or caution.
60 years ago I remember looking at pictures of cars in magazines like Car Craft, and Custom, that were having their tops chopped and the top almost always had to be 'sectioned' to to make top the proper width and length to mate up with the body that it had been cut from.
I think to a certain degree, (hopefully minor), that's similar to what you're facing here.
Good Luck! It's interesting, (a pleasure!), to see how seriously you take getting this RIGHT!
Regards,
Alan

 

If i remember right , its been a while.... your 55 3/8 measurement seems about right. i just measured one of my conversion tails and the distance from the flange on the car to the tip of the duck tail is 6" , give or take a 1/4. also if my memory is right the top half of the 69 rear should be close to fitting , the lower corners are where the big mismatch is , again if my memory is right the lower corners of your 79 really tuck in at the bottom compared to the 69. if you can find a way to temporarily attach the rear clip , even if there are some mismatches and overlaps , doing that should tell you how things are looking as far as length , believe me when the tail is too long or at the wrong angle it will jump out at you. if i can be of any more assistance , i will be happy to oblige

 

The measurement I got is 53 & 3/8. I'm going to check the width of the ACI rear clip at the 6 inch mark again based on what you're saying and the picture of Josh's 82 with 69 rear I posted which appears to be around the 6" length as well. On Josh's car the upper deck areas appear to be a perfect match (not a perfect match on my car at the 8 & 5/8 mark although the width looks right) but like you say the quarter panel area not so much.

 

I was just looking through some pictures of the early stages of my conversion and i may have given you some bad information , according to my pictures ( not my memory ) the upper corners of the 69 tail are narrower than the 79 body and from the pictures took a bit of filling. somewhere close to the style line the tail and the car matched up and from there down the 79 body was considerably narrower than the 69 tail. again according to my pictures i cut the lower corners off the tail and started from scratch , the dogleg on the bottom of the body was just too much to deal with for what i was trying to do. maybe in your case it won't be a problem.

 

This is the hard part.

At least until I get to trying to make the bumper brackets fit my 79 frame, LOL.

 

I just measured the distance on my 72 , 53 3/4 rear door opening to tip of duck tail , 79 conversion 53 7/8 , sorry for the typo earlier

 

Thanks dtamustang, I'm going to check this all again very carefully.

 

Hi P,
Just how that front edge of the fender was finished at the lock pillar jamb could affect that dimension by a small amount and be part of the reason you're seeing a difference in the dimension from car to car.
I'm seeing 53 3/16" on the right side, and just a hair shy of that on the left side…. it's a 71 coupe.
I'm measuring right along the 'crease' at the top of the fender.
Regards,
Alan

 

Thanks Alan, I was initially thinking the 53 & 3/8 measurement I had was off by as much as 3 to 5 inches, you and dtamustang have verified that that's not the case.

 

Hi P,
If I were doing this, (the world is REALLY better off that I'm not), I'd want to figure out the bumper bracket situation before the taillight section is bonded in place.
I wouldn't want a bonded in place panel to put me in a corner bumper-wise that could have been avoided by a mock up at this point.
Regards,
Alan

 

I received a nice part in the mail today.

OEM grill in close to like new condition. I got it for about $15 or $20 Cdn less than a new reproduction piece and found it in Canada so shipping was less than if it would have been coming out of the States. My estimated costs to complete the project are a little more than the amount of money I have left so I'm taking my time and trying to find bargains wherever possible.

 

I'll give some more thought to that. Off the top of my head I don't think I can really sort out the bumper brackets until the tail light section is in place and I'm not sure if the fiberglass wouldn't get damaged if I had it temporarily held in place while I wiggle around with bumper brackets and try to make them fit. Perhaps I can put it temporarily in place and hold the bumper brackets up and see if there's any obvious problems requiring a different location for the tail light section.

 

Priya,

What Alan suggested is a VERY GOOD SUGGESTION...and I would have to agree 1000%...and it seems that you might be using that to your advantage.

If your Corvette were in my shop. I would attach the rear clip but NOT bond it or laminate it in. I know I could secure to so I could do all my brackets and such. So in the event...I need to take the rear clip section off. I could and do whatever I needed to the frame, etc.

Knowing that you have to get this new rear tail section bonded to the quarters and upper deck panel. I would not loose any sleep over me having some areas where I fashioned in an anchoring method to hold the clip in place and have it be solid as a rock....and cause me to ahve to do a little bit more lamination. if the seam between the original panels and the new rear section is wide enough for a bolt to go in between these panels...then that can be how you secure it with wide pieces of metal or whatever that can be used to pinch the panels together and hold them

DUB

 

Okay, sounds like I'm going to be getting into sorting out the rear bumper brackets much sooner than I expected. While I can come up with a plan for the brackets and maybe do some of the initial work before I bond the rear clip in place I think I should have it bonded in place before I do the final fitment of the brackets as the rear clip is likely to be in a slightly different position after its bonded in compared to when its just mocked up in place.

 

Well, I just came back from the garage and checked my width measurements very carefully. The width of the 79 rear and the width of the ACI rear match at 8 & 1/2 inches from the ducktail. The cut I currently have in the ACI clip is at the 9 & 1/2 inch mark and when I hold it up to the 79 rear it is a bit too wide. I just don't know what to make of this given the length on a chrome bumper car from door to ducktail says I should need around 6" of the ACI rear clip and the picture of the 69 rear on Josh's 82 seems to show about 6" as well.

Tomorrow I'll cut another inch off my ACI rear clip and hold it up to the 79 and see how it fits.

 

You forgot the other half Silicone in a tube.

If you need entertainment watch RED-GREEN do custom cars and repairs ... Like the bus into a 2 seat sports car...



She is doing a great job. The work on her car looks great, I can't wait till it's done.

 

as always , this is just an opinion. i think you are going to have to do quite a bit of filling and fairing in the upper corner areas to get them looking right , the reason i say that is , if you get the tail section to fit with minimal filler in the top corners ( line up the measurements of the tail with the measurements on the body ) the rear of the car is going to look stretched out or way too long in the back. after a lot of fooling around i just went with the rear of the door opening measurement to get the duck tail in the right location. once that is located and looking right , everything else will be where it winds up being. again , in my opinion , get it looking like you want it to look from the side , the duck tail at the proper angle, the tail of the car proportional and let the seams fall where they may. fill and fair as needed

 

I discussed with my husband and he felt that a couple of inches longer wouldn't be noticeable plus at six inches there'll be no room at all for any of the 79 crash bar but with a couple more inches I might fit part of it in. I think what I'm going to do is take another inch out of it so the width is the same trim the quarter panels to match as close as possible, temporarily mount it in place and see how it looks then and how it looks like the bumper brackets will go and then decide if I want to take more out of the ACI rear clip.

I guess what I don't understand is how on Josh's car the width of the 69 clip he used seems to match perfectly with the width of the rear of his 82 and he only seems to have used around six inches of the 69 rear clip.