firewall fabrication (help me )

[WVUFELLA]

well guys sorry to say i am goin to have to do some surgery on my girl. While stripping the firewall I noticed that where the master cylinder and that backing plate bolt on to the firewall there is some cancer that has got thru. My question is  has anyone else had this problem and how did you go about fixing it.Obviously i dont want to cut any more than i have to.

[Challenger6pak]

Can you add some pics?  Thanks

[miketyler]

Yep - been there, done that. mine had serious rust behind the booster but also large holes inside the cowl duct section and very thin cowl floors. Because of the holes and the thining metal in areas I opted to replace it. Half the job was finding a donor. The other half was getting someone to do it for me. 

You can make out the big holes in the cabin side of the cowl on the drivers side if you look closely     

[FY1443433]

 

WVUFELLA,

Cuda and Challengers are notorious for rusting in those areas.  You have several choices  but it's up to you, either you fix what you have or replace the complete firewall.  Complete firewalls can be expensive and hard to find because they might be worse than what you have. 

Good Luck
FY1

Goodluck

[WVUFELLA]

It doesnot look to bad. I think i can get away with just cutting out a piece then fabricating a replacement piece. Mine is right above the master cylinder and that backing plate. I am gonna try to cut it out tonight and then fix it up.  I dont knwo i guess time will tell. I dont have the connections to get a replacement firewall or the $$ so i think i am gonna have to do it myself . hey guys thanks alot for the advice .... always appreciate the info

[WVUFELLA]

hey guys here is a pic

[miketyler]

that doesnt look bad at all. I would however, pull the cowl screens and look around real good inside the cowl box section with a mirror and flashlight.

[dougs bs23]

you can easily fab a new piece to repair that if you have the basic tools and some pateience.  Take the cowl off, get a new section of metal (20 ga.) Cut it about 2 inches bigger that the area you are fixing.  Overlay it on the top of the wall and form the downward curve, After you have done this, using your stretching, shrinkiing hammers slowly work the metal into the contour of the existing section.  You may need to make a slice in it to get the diagonal angle of the top (down towards the wiper motor) Take your time and it can be done  After you have the shape you want with the new pieve still overlayed on the original using your cutoff tool or sawzall cut through both sections and your new one will lay right in the area.. Weld it up, (Not to hot)  Grind the welds down flat and skim it with some body lead to seal any small pinholes in the welds.  IT worked for me, took about 3 hours to do it and once it's painted good and the cowl is put back on  it will look as good as new  (I hope)      hope these pics arent to large,,,

[FY1443433]

dougdel,

 

That's very nice work.

FY1

[dougs bs23]

took some time,  and as you can see, i didnt take the lead down flush,, but it gets covered by the cowl so I'm not gonna worry about it.  but I will apply several good coats of paint to it before the cowl goes on,, that is one thing I noticed  that  ooppppps the factory didnt paint it.  so thats you.  I did the same thing with the roof where it was rusted along the rail under the vinyl,, cut it out,, formed new meatal,, welded, lead and a thin skim coat of body filler and spot putty

[Timmy C]

I am in the same boat with my cuda.  I am kind of looking for a replacement before I start fabbing.  Is the firewall specific to cuda and challengers, or did some years of the b-body share these also?

[moparclown]

i have been told 71 and up b-bodies are the same.thats only what i have been told i have not been able to verify this as of yet.

[miketyler]

This seems to come up time and time again. Ebody firewalls are exclusive to Ebodys. Other models have pinch welds in different locations and may seem similar until you look close. I think the B-body has the large arc-shaped pinchweld instead of the lap joint used on Ebodys. Its a night and day difference.I think some of the other 70-74 mopars have wiper motor boxes that are similar and perhaps could be used in a pinch.

[dougs bs23]

you can find a few out there if your willing to pay for them and as for "B" bob's,, well simply put the answer is no but i guess if your creative enout=gh you could make it work,, IMO if the damage isnt to severe, with time  and patience its easier to make the repairs.