Since I have my engine out, and I will be repainting at some point down the line, I thought it might be a good time to smooth my firewall. The heater box hole, and fan hole are already filled. I guess I need to know the easiest way to do this. I have several areas on the firewall that are deeply recessed due to multiple engine installs and clashes between the block and firewall, and before I swapped to the 327 engine mounts I had to dent the firewall for my HEI clearance. I don't want to simply fill these areas with bondo and then sand. I would prefer to either cover them with a flat piece of steel and tack around the edges, and then bondo over the seams. Since I don't want rust to start in the cavity-how do I protect those areas that will be covered? Should I use a body slide hammer and try to pull these areas out and then just weld up the holes?

What is the BEST way to do this? I don't want to cram a bunch of body filler in the car, only to have it bubble or blister later if water gets to the filler.

Next, what primer should I be using? Do I need to seal the area before I spray? Should I clear coat it? Is wet-sanding necessary?

I have bascially the same situation, where my firewall was beat in to fit an HEI. I tried a slide hammer, but was not able to pull the seam between the the firewall and the upper cowl out. It work on some of the other areas, but not at the seam (3 pieces of metal there). I had to use a BFH and someone on the other side with another peice of metal to beat against. This is where I stand right now, but I have already made a temple from cardboard and will be transferring that to sheet metal for the entire left side and up over the trans tunnel on the firewall.

I took the firewall to bare metal (used a Harbor Freight Bead Blaster) and then sprayed expoxy paint over the whole thing. Where the seams of the sheet metal will be I have Weld thru Primer there. I am planning on welding the entire seam of the sheet metal, so no sealing should be required. Maybe a little bondo (depending upon how go the weld comes out). Since this is going to be out of the direct light I am going to leave the firewall under the sheet metal just in expoxy.

Once everything is complete the firewall and innner fenders will be painted the body color. Only then will I do any sanding.

So you are going to paint yours body color? I have been debating on that. I am not sure what color I want to go with mine. Since I will be painting the car Cortez Silver, I was thinking about going with a different color.

My line of thinking was that if it was a different color, it would contrast with the exterior body panels-and make the engine compartment look nice. I guess it is hard for me to visualize what the underhood area would look like if the firewall, inner fenders, braces, core support-EVERYTHING-was painted body color. I know for sure, I am going to use the black paint sparingly as I don't like the spray bomb look under my hood.

I like the idea of covering the old metal with a new flat piece and welding it in place. I understand what you are saying about welding it all the way around to seal it up-but I don't believe that is possible. Water can get in between those panels from the cowl area if there are ANY points of entry (heater hose hole, heater box, fan hole, seam) and then be trapped in there to cause trouble.

I think I am going to try and stick to getting my current panel as flat as possible by welding in patches cut for each specific hole and butt welding them in. I will still need to decide what color...

If I paint the firewall body color, I would like to paint the inner fenders a different color entirely. Perhaps I should just keep this simple and leave everything else black, but re-paint it with a better paint so it looks better.. I'll cross that bridge when I come to it as they say. For now, I have some welding to do..

I was going to try to do something like that as well. My neighbor has a 80 trans am that he placed a sheet of stainless over the firewall that looks really slick.

His car has a better flowing line across the top however where the first gen camaros have a curved radius. A bit more difficult to bend. Im still working on that issue.. Im also going to attempt to relocate the wiper motor way to the passenger side of the cowl.

Detroit Speed has a panel that is cut to fit where the heater fan motor and heater core nipples are. The panel was clean looking and would fit perfectly.
You also could make your own.

I purchased the detroit speed fire panel. It does fit well, but I will still have a seem around the edge. What do I do about that?

We had to beat back the firewall to accomodate the HEI. With the VintageAir, I was able to have the heater box hole smoothed. I need to get in there and detail, but you get the idea. It'll be alot easier if your motor is out and you can have the front end off. You'll probably need to work it from both sides and someone on the otherside backing up your swings will help. Obviously you'll need some filler to make it really smooth. Good Luck.

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