I would mount it in place drill the holes bolt it all down. When the welder is available it'll be ready to go, should you decide this is what you want to do. Now, there are body adhesives that are very strong. My 2004 XK-R was all aluminum body and was riveted and bonded together with adhesives.
Also, If your car will experience the rigors of auto-X and or road racing, welding that angle is of more paramount importance as it spreads the stress from these activities more along the leading edge.
Some of this too, will depend on where you are in your build. If your firewall at this location is "finished" and you don't Auto-X or road race, I see no reason why you can't simply clean to bare metal (based on body adhesive guidelines) the area in question, glue it in place and have minimal paint repair.

 

Install as it normally should be and when a welder is available weld it

 

Regarding bonding, below are a couple threads I had bookmarked. A guy and his kid were testing bonding adhesives compared to welding 10 plus years ago. We skipped that bracket on my car years ago. Since it's all put together, I'm not too excited about trying to weld it in now. I'd glue mine, just waiting on motivation and hopefully some use for the rest of the tube of adhesive. I hate to use a little of something and then have to throw the rest away.


Welding would be the period correct way of doing it though.


Welding or Bolting vs gluing panels on, a science project....
Follow up peel test from my sons science project on Welds vs Glue.
Real world test on panel adhesives, check this out!

 

Did real export cars have this plate or is it a Shelby thing?

I but my export brace on without the plate. Not saying it's not needed, just saying that it's what I did.

 

When I got my 70 back in 1995, it already had a chromed export brace. And I’m fairly certain it doesn’t have the reinforcement plate.
I’m still not sure why the reinforcement plate is needed.

 

Pictjures or measurements of the brace?

 

Export brace

All of my early cars have/had the and I'd guess I installed a few hundred in the old shop. NEVER needed the reinforcement plate. I doubt if you'll ever bein a driving situation where that little extra piece will ever improve anything. Even my 65 K GT FB doesn't really need it!

 

Adding an export brace is on my project list. I have the drake bar and the extra supporting plate in hand. However, I don’t have access to a welder, at least in the winter. ....."

you'd be surprised how many great welders will go on location for you, and it won't cost you an arm and a leg either.

"........How many aren’t using the extra plate now?

I've seen maybe 50- 75 cars w/o the support plate come thru various shops I've been associated with over the last 5 decades. About 90% of them had egged out the mounting holes on the firewall. Sooner or later, if you like to go around corners faster than grandma, or take off like a jackrabbit, those unsupported holes will get egg shaped sooner or later.

Now if you just want to putt-putt then no welding is needed.

Z

PS If you want it to look factory like the Shelbys, etc. then smear on lots of seem sealer after the welding then just pour some paint out the can on the whole mess. That's how most of the Shelbys I've owned or seen looked like

 

So did only Shelby’s get them or did export cars too?

I have a buddy with a mig welder, but it is flux core and we haven’t had good luck with it. I suppose tacks don’t have to be pretty.

That area of my car is just rattle canned so it shouldn’t be too bad to retouch when done. Just tack around the outside of it? I’d rather do that so it could be removed if for some reason I wanted to do a concourse car. (I know, won’t happen)... versus perminately bonding it.

 

So did only Shelby’s get them or did export cars too?

The early Shelby's just recieved the export reinforcement package at Fords assembly line and the plate is a part of that. All Mustangs that had the export brace mounted at the factory, also had the reinforcement plate welded on.

 

Glue it. They use glue on modern cars. Thats even the factory demanded way of doing a lot of body repairs. Just use the same type of glue that they use in modern body repair shops.

 

Somebody (Maybe 22GT or zray) has posted photos of some of the Shelby installations and the welding looks like a mud dauber did it. Welding the thick gauge steel of the reinforcement plate to the relatively thin gauge steel of the cowl is not easy without burning through the cowl. It's not a job for an amateur.

 

I made a stiff L shaped lower bracket that butts tight against the firewall. With it, the Drake export brace, and the 4 bolts sandwiching the the cowl I feel it offers support nearly as well as any half *** welding to the firewall.


The main reason that I never attempted to weld it on (besides the difference in metal thickness) is that the insulation pad on the inside of the firewall would first need to be removed. The fibers that face the firewall are highly flammable when enough heat is applied.

 

Thats probably the way the OP should go, no welding and no ugly like the original brace. I did the same thing with some 1/8" square tube that I cut as needed into a L shape. The rounded corner of the sq tube fits the firewall best. I drilled and plug welded mine and caught the seam sealer at the cowl on fire! It still stinks a year later. If I were to do it again I would probably weld studs onto the angle and bolt it through the firewall. Same look, no fire extinguishers!

 

Good points above.

 

I don't plan on driving mine hard but for the short amount of time to weld it in and the relative low cost of buying it I opted for a little more strength in that area.

 

I also redrilled my holes and used 1/2-20 Gr8 bolts and nuts with thick flat washers on the underside and red threadlocker.

 

Good idea on the hardware and some threadlocker.

 

If elcheapo ford welded them in.....I wonder at what point in the production line this was done.

 

FWIW, The welds don't need to be a continuous bead all the way around the plate. A very few beads are going to to eliminate the possibility of momement and you are good to go. There was so much (original ) seam sealer on my Shelbys that one couldn't see all of the welds , but it , the welded area, wasn't very much.


Z

PS. Yes, Ford installed the export braces. It's well documented they were in place before arrival at the Shelby facility

 

Thanks all for the input.