I went down to my Dad's place yesterday (where my truck is being stored) to re-evaluate the shape of things. I am planning to order patch panels soon so I can start on the cab. Over all the cab is pretty solid. However the PO wanted more room for the engine and hacked up the firewall pretty good. He started to weld part of an old wheel barrel into the center to accomplish this but never finished. After looking at it closer I am beginning to see why he didn't finish. He's got the firewall so chewed up that it would take hours of custom patch making and welding to get this thing to look right.
I think I'm going to need to replace the whole firewall and start over. Is there any technical stuff I need to know before doing this? The truck still has the dash in it.
Do I need to weld in braces inside the cab to keep the thing square before taking the firewall out? Of coarse thats assuming the cab is still right after the PO's butchering.
I took a quick look at mid-fifty and it looks like they have 2 options; stock (which is sold in two pieces, drives side and passenger side) or a solid piece that extends the engine compartment into the cab another 4". I am going to go with a 302 and a C4 or maybe an AOD.
Do I need this extra 4" ? If I so Mid-fifty's web site says that this firewall is designed to go with the 4" extention floor and kick panel kit as well. Do I really need these as well or can I make the floor that is there and solid work?
Maybe I'd just be better off looking for a better cab. However the floor, cab corners and roof line on this cab are all in good shape.

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Thanks

 

302 is tiny, you don't need that 4 inches.. now if you were jammin in a V12....

and I would brace side to side no matter what.. simple 1in sq tubing and 2 welds..
and if not doing the floor, I'd brace them to the crossbar as well..

I replaced the front floor an toeboard with 14ga, in 2 pieces. then built a smaller tranny cover..

Sam

 

is the truck stock or subframed?

 

Sounds like you got part of your question answered?

I have an extra cab I'm trying to get rid of, in pretty good shape, plus another scrap cab I was just about to butcher up tonight but ran out of time and motivation!
plus I was thinking about what panels someone could possibly use off of it for fixing a cab? im going to use part of the dash on my truck where a PO had cut out the radio opening with a torch! well ok it wasn't with a torch but it was hacked up good.

Alas I looked in your profile and see you have a 53? these are 51 52 cabs, so probably different firewalls? you could just have this firewall for free if it would work, better you than the scrapper!

Im going to post an add for any sheet metal pieces anyone may need for shipping costs before it gets cut up.

cheers

Josh

 

As has been said, you don't need a recessed firewall for a SBF or even a BBF for that matter. Here is a pic of my 56 with a flat firewall and a 302...there's plenty of room. The only question that you really have is whether you want to stay with a stock stamped firewall or go with a custom unit. I would recommend that you contact Direct Sheetmetal, they can make whatever you want...my firewall is made of 14 ga steel and is held in place with structural adhesive. I'm not in Keith's league but I have been known to break a few rules...

 

You've just cleared things up for me Charlie with that picture and your indorsement of both small and big block ford fitting. I have a 56 pickup that I plan on putting a 351w in and the firewall is need of repair. I like what you have done as it is very clean looking. The lower outside corners I take are from the original toe boards? Nice looking front runner on your motor as well, is that a Vintage Air unit?

 

|remember, this is just a cover (excellently done tho!).. so the original firewall (in all its prior ugly state) is behind there..

oops, I misunderstood.. way more beautiful work.. never mind, ignore me!

Sam

 

Thanks guys

Like I said my firewall is already pretty chewed up. Is there a resource that would have some measurements I could take inside or outside of the cab to make sure it is still straight. I would hate to brace it all in place as it is, only to find out later that it was all out of wack to begin with.

Gotta love PO's

 

I guess that there is a little misunderstanding about what I have done wrt this firewall. The old firewall was completely removed, the only part that remained was a 1 inch flange around the outer edge of the firewall which served as a support to which the new firewall was glued. Here are a couple of new pics that should clear things up a little. As for bracing...I don't brace, the structural integrity of this portion of the cab comes from the vertical and horizontal cowl members and not the sheetmetal in the firewall. Some folks tend to be very cautious and want to brace, if that makes them feel better about the process then that is what they should do. Whatever course of action that you take, always measure to ensure that the dimensions are correct before you weld or glue. The other issue that arose (mostly from members of my truck club) was the removal of the center recess in the firewall. Once you understand why the recess was put there in the first place it's easy to see why flattening it out makes no difference if you are running a V8 instead of an I6.

 

as long as your cab is on the frame and the doors close well then it shold be close as far as being square. if the cab is off the frame then you would have problems with the cab flexing. also the frame should be sitting level on jackstands before starting repairs.

joe

 

Yes, the lower corners remain from the original toeboards. I chose the mating points for the replacement panel carefully based on two premises; first, the replacement panel was not going to have any complex curves and second, the lower corner mating points would have an overlap along the edge where the inner fender attachments are situated. You have a good eye for the engine accessories, this is a Vintage Air frontrunner setup. I bought the polished version but found that not everything is polished...the aluminum water pump was delivered in its cast form. $80 later it looks like it fits the rest of the components. I am very happy with this system so far, I am sure that it will perform well once I start driving the truck.

 

See my "making changes" gallery for the firewall smoothing I did to repair the hack job a PO did when installing a hanging clutch pedal and FW mounted clutch MC. I left the recessed section in the center of the firewall because the dizzy on my CSB fits perfectly in it.

 

Thanks for the additional photos Charlie, I'll have this book marked for the future.

 

Yes that recess I believe old Henry put there for us darkside folks,lol. Obviously he had no problem with anyone trans planting,

 

Like I said once before ...had Henry wanted us to use an engine with a front dizzy, he would have put a recess into the radiator instead of the firewall.

With the 53-56, the dashboard, upper cowl, cowl sides and floor are all welded together and keep the cab in alignment and rattle free. unless you are cutting away the floor and/or the roof the cab should not require any extra bracing while cutting away and replacing the firewall either with a stock contour or flat panel. If using a flat panel especially and welding it in place be sure to go slowly with short 1" tacks spaced as far apart as possible and allowing each to completely air cool before adding another. A firewall may take a couple days to weld in completely, but it will be worth the time compared to trying to "chase the oilcan" to remove the heat warps you'll be sure to end up with if you rush it.
Mr N, I'd suggest going to your CP and adding the year and model of your truck to your signature so it appears in all your posts.