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Cowl Alignment Help Needed

568 Views 12 Replies 8 Participants Last post by  RudeMan
Hey folks. After a lot of patching and reconstruction work I’m finally getting close to welding in the replacement upper and lower cowls on my 66 Vert. But before I make mistakes I can’t easily correct I have a few questions.

1) In terms of the fitment, what is the best method of making sure everything lines up in the end, doors, fenders and cowl ? Is a test fit with fenders installed the best way. Doors are still on the car.

2) Also is it best to weld the upper and lower sections together first and then weld in the entire assembly.

3) Finally, what is the optimal hole size to use for the several hundred plug welds in the lip of the vents.

Please don’t limit your comments to these three questions as I’m sure there are things to consider I’m not aware of.

Many thanks for the help.
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Doors, fenders, cowl, and hood.

Eventually, the whole body should be fully assembled, right down to the headlight doors. Before any painting is done.
 

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Always assuming you have the lower cowl in the correct spot There are alignment holes on the cowl(only pic I have illustrating them):


I have the extension dropped through the alignment hole on this side while matching up the windshield line. I also used the fenders to make sure everything looked like it was supposed to, didn't have a hood at the time, but no issues test fitting one later. I will qualify this with the fact that while I used an aftermarket lower, I restored the OEM upper cowl and re-used it...so I couldn't speak as to how aftermarket cowls fit.



Also, the export brace holes are used for alignment purposes up front.
 

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Hood Automotive tire Motor vehicle Bumper Automotive exterior

Hey folks. After a lot of patching and reconstruction work I’m finally getting close to welding in the replacement upper and lower cowls on my 66 Vert. But before I make mistakes I can’t easily correct I have a few questions.

1) In terms of the fitment, what is the best method of making sure everything lines up in the end, doors, fenders and cowl ? Is a test fit with fenders installed the best way. Doors are still on the car.

2) Also is it best to weld the upper and lower sections together first and then weld in the entire assembly.

3) Finally, what is the optimal hole size to use for the several hundred plug welds in the lip of the vents.

Please don’t limit your comments to these three questions as I’m sure there are things to consider I’m not aware of.

Many thanks for the help.
I’m replacing my lower cowl panel right now. I drilled 5/16” holes every 1.5” or so. My upper is the factory one, so I will plug weld the 3/8” holes I had to drill to get it off after the lower is installed. Because I’m using my stock one I have alignment drill marks at the windshield and apron extensions from drilling them out. Going to take my time and not be afraid to hammer the crap out of it if it makes the upper cowl fit how I like.
 

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as stated, there are alignment holes for the lower cowl install along the hood edge and both sides. Weld that one in first, then the upper. Be careful to ensure the wiper arms are centered in their respective holes. As a helpful hint- make sure to remove the lead from the lower corners of the windshield before welding... ask me how I know... lol
 

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Don't forget about your hood. You want the beauty lines on the hood to line up with the lines on your cowl. I'd just test fit/mock it all together before you start welding anything. And I'd weld the lower piece in first. Then the top. If you weld them together then try to fit in you don't have any wiggle room now for slight adjustments.
 

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1) In terms of the fitment, what is the best method of making sure everything lines up in the end, doors, fenders and cowl ? Is a test fit with fenders installed the best way. Doors are still on the car.
Place your bottom pan in and secure with a couple sheetmetal screws, then top pan. Put on entire front end (fenders, hood, doors etc) and adjust from there. You really want the car at least loose assembled so you can get the gaps right.

2) Also is it best to weld the upper and lower sections together first and then weld in the entire assembly.
No. Weld the pans in separately. Bottom pan to the car first then top pan to that (after the above step has been done and your reference points noted)

3) Finally, what is the optimal hole size to use for the several hundred plug welds in the lip of the vents.
I used a Harbor Freight spot hole cutter to make the holes in the new cowl. Same one I used to remove the factory spot welds.

You can see my cowl job in the link below.
 

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Discussion Starter · #9 ·
thanks so much folks. This gives a really good strategy. the driver side kick panel guide hole is gone completely because I had to section in a rust patch. So ill Do the full mock up for sure. The doors never did line up with the fenders anyway so hopefully I can correct some of the bad fitment.

Really appreciate everyone’s responses. I would never have taken on this cowl replacement if it was not for the encouragement of this community. And I’m a pretty crappy welder but I seem to be getting the job done, even if at a glacial pace !
 

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Discussion Starter · #10 ·
1) In terms of the fitment, what is the best method of making sure everything lines up in the end, doors, fenders and cowl ? Is a test fit with fenders installed the best way. Doors are still on the car.
Place your bottom pan in and secure with a couple sheetmetal screws, then top pan. Put on entire front end (fenders, hood, doors etc) and adjust from there. You really want the car at least loose assembled so you can get the gaps right.

2) Also is it best to weld the upper and lower sections together first and then weld in the entire assembly.
No. Weld the pans in separately. Bottom pan to the car first then top pan to that (after the above step has been done and your reference points noted)

3) Finally, what is the optimal hole size to use for the several hundred plug welds in the lip of the vents.
I used a Harbor Freight spot hole cutter to make the holes in the new cowl. Same one I used to remove the factory spot welds.

You can see my cowl job in the link below.
Thanks for the link Excelr8. And amazing job on that coupe. couple of questions. What did you coat the bed of that lower cowl with ? And regarding the mock up, my export brace was a good 1/4 to 3/8 wider than the shock tower holes in terms of lining up. So there has definitely been some deflection or some collapsing over the years. How will this effect if at all the mock up ? Well I guess I should mock up with the export bracing installed.
 

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Thanks! Yeah, nearly 10yrs of work but enjoyed every mile this first summer driving it :)

I bought a gallon of Duplicolor Bed Liner from Advance Auto and used that on the lower cowl pan as well as the underside of the upper pan. Complete bottom of the car and my interior floor pans have it as well.

If you plan on using that export brace I would include it in your mock up. If your shock towers move in or out with or without the brace installed, that means your fender bold holes in the upper aprons are moving as well which also determines where you fenders will sit. Now there's some adjustability left/right/fwd/back via the fender bolts, but more you can assemble up front the better.
 

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Discussion Starter · #12 ·
Thanks, I’ve got a little more reconstruction to do in the lower windshield corners and the step where the cowl assembly rests on. But then I can start mocking things back together. Thanks again to everyone who replied.
 

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Discussion Starter · #13 ·
Always assuming you have the lower cowl in the correct spot There are alignment holes on the cowl(only pic I have illustrating them):


I have the extension dropped through the alignment hole on this side while matching up the windshield line. I also used the fenders to make sure everything looked like it was supposed to, didn't have a hood at the time, but no issues test fitting one later. I will qualify this with the fact that while I used an aftermarket lower, I restored the OEM upper cowl and re-used it...so I couldn't speak as to how aftermarket cowls fit.



Also, the export brace holes are used for alignment purposes up front.
Thanks Wicked for the images. Man that is an extensive job. I think I’ve elected to do more patchwork than you. We’ll done !
 
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