Hard to swap out tops on Challengers?

[bb71challenger]

I cut the top off one of my parts cars for a buddy who just rebought an old Rallye Challenger. The guy who had it parked in under a window a/c unit for over 10 years and it totally rotted out the top. Once we drill out all the spot welds and take everything to the factory mounting points, how hard is it to get it in there right? It looks to me like besides measuring the old top, the new one should pretty much slide right in to the same spots as the old one. Any tips on this? I do have a mig welder with 75/25 and can do all the welding but have never welded sheet metal before. It is an original white vinyl top car and he plans to put one back on when its done. Any tips would be greatly appreciated.

[Chryco Psycho]

having the front and back window handy to fit would obviously be helpful

[Chlngrcrzy]

I had a heck of a time finding and drilling all of the spot welds on mine, but i was more interested in just getting the thing off, so i didn't spend much time trying to save it. But i would think that it should slide right into place, be careful removing the good one so you do not get any bends or creases in the metal as you pull and pry. I replaced mine with a new one from AMD and it fit ok.

[bb71challenger]

Thanks guys. I gave plenty of room for error and took it off with a saber saw. No prying needed, just pickit up and put it in the truck bed. I tellya, that saber saw has more than paid for itself just in time saved. I took the end off a parts car a long time ago with a torch and it took a while and produced noxious smoke from the seam sealer and undercoating. I swear it only took like a minute tops to cut the last one off and not much more than that to cut off a roof. He still needs to drill out all the spot welds and prep it for welding. The tip about the windshield and backlight  definitely makes sense and we will surely do that.

[1970RTSE]

I am currently doing a roof swap from one parts car to the project car.  I removed the seam sealer by lightly heating up the underside with a small propane torch.  The seam sealer just about pealed off by hand. I drilled the spot welds with a 3/8" cutter.  There are about 40 to 50 along each drip rail and about that many at each window.  I used a small die grinder to remove the stich welds at the quarter panel seam.  The welder who put togther the project car must have been new to the job and just about seam welded the whole C-pillar joint.  The parts car on the other hand had three little 1/2" stitch welds.  Although having the glass is a good idea, I am not sure its necassary.  There is about 1/4" tolarence on the panels from what I can tell measuring various cars.  I recall having almost 1/2" of room round the top edge of the rear glass and over 1/4 on the bottom edge.  I don't think you could screw up installing the new roof panel by 3/4" and still be able to weld it.  I will tell you not to expect the new panel to sit exactly where the old one did.  Again, do to manufacturing variances, and assembly tolarences, there will be differences in gaps.  I'd use many pairs of vise grips or c-clamps and work from the middles to the corners.

[bb71challenger]

Oh man that sounds involved. I was hoping to leave the drip edges on and just weld at the pillars. 

[1970RTSE]

Oh man that sounds involved. I was hoping to leave the drip edges on and just weld at the pillars. 

You could, but I would not trust the integrity.  The inner structure is full of overlaps and odd shapes.  I can post some pics of the inner structure.  Remember the maximum stress is at the corners of the a-pillers and c-pillars.  I think the spot weld removal methode is the best to retain structural integrity and its not that bad.

[Chlngrcrzy]

You could, but I would not trust the integrity.  The inner structure is full of overlaps and odd shapes.  I can post some pics of the inner structure.  Remember the maximum stress is at the corners of the a-pillers and c-pillars.  I think the spot weld removal methode is the best to retain structural integrity and its not that bad.

I agree. You will be really surprised at how easy it is to drill out the spot welds.

[DMZ73]

Been there, done that.
Nah, it's not that bad. In fact it is probably worthwhile. Drill, drill, drill. Wear your eye protection, and have a few extra bits.
once you are through all of the welds, it just pops off.

You can see my progress here:
< http://www.pbase.com/dmz73/image/63591642 >
< http://www.pbase.com/dmz73/image/67929548 >
< http://www.pbase.com/dmz73/image/72546236 >
< http://www.pbase.com/dmz73/image/72546223 >
< http://www.pbase.com/dmz73/image/72707932 >
< http://www.pbase.com/dmz73/image/78134185 >

Since I had to do a LOT of fab work on my roof after removing it from it's donor "shell" I would recommend purchasing a new one from AMD if the one you might graft is worse for wear.
In Fact, I wonder if I should do the same thing.

Dan .
Dan

[bb71challenger]

After getting an R/T hood from Goodmark and then listening to people talk about the softness of the metal and thickness, I am wondering how a new roof like that would hold up to all the little hail storms we have out here. I know the big ones will dent anything but we get hail every year that is pea to marble sized that never seems to faze the older cars like our beloved E-bodies. I am wondering if one good storm like that would leave the roof looking nasty.

[DMZ73]

Yeah, I wonder if the thickness is consistant with a vintage one.
I can tell you this: They are flimsy  no matter what. Once you start cutting and patching, you are dealing with a flimsy, easily warping surface.
Once clamped from the center outward, the skin retains its strenght quite well.

You could do like I have done. buy a donor roof, drill out all of the welds, and  viola, one roof skin.
 (Hopefully you don't have to patch the living heck out of the skin like I did)

Dan

[bb71challenger]

Yeah I have a donor roof off of one of my parts cars. I just did not know it involved drilling out all the spot welds on the drip edges. The roof is in pretty good shape, a couple of dings but for the most part still has pretty decent original white paint on it.

[DMZ73]

Lucky man.

Drilling out the welds is easy in comaprison to all of the fab and cleanup I had to do, not to mention wheeling out the roof of all of the adhesive, surface rust and gunk.
Dings are super easy to get rid of. I would be more than happy to give you any tips. I had to do it the hard way. I happened upon a roof for $150 within 2 -3hrs away, and I just drove to get it once I saw the pics. It looked "decent" Little did I know how much it really needed.

Did you see what I had to work with?
< http://www.pbase.com/dmz73/image/72322716 >
< http://www.pbase.com/dmz73/image/72322717 >
< http://www.pbase.com/dmz73/image/72707933 >

dan

[1970RTSE]

Yeah I have a donor roof off of one of my parts cars. I just did not know it involved drilling out all the spot welds on the drip edges. The roof is in pretty good shape, a couple of dings but for the most part still has pretty decent original white paint on it.

I have been keeping a log of the work I am doing.  It took me about 9 hours to remove the roof off my project car, and off my parts car.  There were about 40 spot welds in each drip rail and about the same for each window.  For some reason, the parts car had a 2' section with not spot welds in the back window.  The hardest was removing the stich welds at the quarters.  The project car must have been welded on by a rookie.  IT was just about fully seam welded.

[bb71challenger]

I have been keeping a log of the work I am doing.  It took me about 9 hours to remove the roof off my project car, and off my parts car.  There were about 40 spot welds in each drip rail and about the same for each window.  For some reason, the parts car had a 2' section with not spot welds in the back window.  The hardest was removing the stich welds at the quarters.  The project car must have been welded on by a rookie.  IT was just about fully seam welded.

Funny you should say that. On my 71 Challenger the seams both looked to be a full weld and nasty looking. I thought it had been worked on but a buddy who has owned many many Challengers said he has seen a bunch that looked just like that. I have not removed the lead or whatever is on the quarter/roof seam on the parts top as I am hoping the buddy of mine drills out the welds and cleans up the seams. If he does most of the grunt work I see no reason why we cannot weld the new skin on ourselves. Thanks for the reply, any information I can get prior to doing it will help me that much more.