Vintage Mustang Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
388 Posts
Discussion Starter #1
Once again I'm finally getting back at working on my car. I removed the cowl months ago and after lots of firewall repair I'm getting ready to install my new 1 piece assembly.

I know I still need to reinstall my doors and fenders to check fitment, but i have three questions.

1. When the cowl is set on the car there is a large gap between it and the dash where the windshield attaches pictured below. I can clamp it together and get it to fit tight, but I'd say the dash closes 2/3 of the gap and the cowl closes the other 1/3. Should I be worried about windshield fitment later or is this common?

2. The cowl seems to want to sit in one place on it's own, and while the alignment holes are very close, only one is right on. I'm sure it will move slightly when I line everything up... but should I expect them to be very close or is it normal for them to be slightly off and to have to remove a bit of material later to align the holes to bolt in the strut to cowl brace? I have the alignment holes and cowl brace holes pictured below as well.

3. I have access to a spot welder that I can borrow. Is that a better way to go than plug welds? I don't think it will fit in the space between the dash and lip to use on the top so it'd only be used on the sides and engine bay side. Does the primer/coating need to be removed for a spot welder?

Thanks!!
 

Attachments

·
Premium Member
Joined
·
5,617 Posts
Been exactly there, done exactly that.

1) Stop where you are and order up a Scott Drake Export Brace and cowl reinforcement plate. Don't cheap out, get the Drake (ask VMFer LowlySlows how we know this).
2) Fit the brace and the cowl at the same time.
3) Grab a half dozen proper sized bolts and nuts to loosely attach at the holes, then go around tightening them down.
4) Clamp the remaining perimeter.

I would recommend hitting the mating surfaces with weld-thru primer. Then scuff to bare metal a weld starting point at each hole. ALWAYS weld to clean metal.

If you want to use a spot welder in places, fine. Practice a few first. I did mine without, but whatever works for you.

Note: Have you checked wiper parts fitment to the cowl yet? Better now than later.
 

·
Registered
Joined
·
684 Posts
I recently went through an experience similar to yours and the only true test is to hang everything. Once you have fitted the upper cowl vent to the best of your liking/ability or as much as it copperates, I would suggest clamping and tack welding as little as you can so that you can hang your fenders, hood, hinges, and doors. I would test fit the windshield glass and weatherstripping? I would even go as far as to test fit the windshield trim. Yes, the primer needs to be removed at the weld if it isn't weld through primer. I would recommend giving the inside of your cowl vent a good coat of primer and sealer while it is exposed as well. How are your gaps at the ends where the upper cowl vent meets the A pillar? Best of luck.
 

·
Registered
Joined
·
1,000 Posts
I did the same as above when installing my two piece Dyna cowl. I secured it all together with sheetmetal screws so I could hang all the parts. The holes aren't going to be perfectly lined up, but long as the fender and such do then it will be fine. I re-drilled the export brace bolt holes, no biggie. My window lip was same way. I clamped the heck out of it, welded then beat back into the proper shape for the windshield to fit. You'll end up doing a little here, then test fitting, then some more, then test fitting etc till its right.

I drilled all the holes by hand and plug welded the entire thing. 200+ or so welds if I remember right. Used weld through primer after grinding the paint off and finished with seam seam sealer. Also coated the insides of the bottom and top pans with bed liner too. It was actually the most fun and rewarding part of the sheetmetal journey for me.
 

·
Registered
Joined
·
4,726 Posts
As said above, what you are seeing is perfectly normal. Almost exactly what I saw. I used the Export Brace to square everything up, put Bolts through the alignment holes and used clamps and screws to pull it all tight. I did Install the lower first, then welded the upper to the lower.

I also have a spot welder. What I found is that it doesn't work well with ANY contamination between the two sheets of metal to include the Weld through Primer. I had to clean off the primer at each weld location, then spot welded the locations where it reached easiest. I plug welded the rest.
 

·
Registered
Joined
·
388 Posts
Discussion Starter #8
Thanks everyone for the info!

I can see how the export brace would help getting everything lined up, but I plan on making one in the future to clear my EFI intake... I’ll scan my local classifieds and maybe I can find a deal on one to use to line everything up.

The whole firewall/dash lips are already in weld thru primer so I’m good to go there. I haven’t fit the wiper parts yet. The cowl I’m using is a one piece pre-welded assembly. Should I still be worried about fitment?

I’m happy to hear that the gap between the cowl and dash is a common thing. That’s what I was most worried about. I have a locking plier addiction (50+ pairs!) so I will definitely be able to persuade the metal wherever it is needed! I’m leaning toward plug welds instead of spot welds, I have a pneumatic punch here so that should help with at least half the holes.
 
1 - 8 of 8 Posts
Top