Ever since I tore out my AC/HEAT unit Ive wanted a nice new firewall, aluminum or shiny steal. Currently I have a piece of steal welded over the AC hole, real classy... :D I pulled my small block and im building a 454+/30 over. So nows the perfect time. I decided to make it myself, so far ive gotten some nice thin aluminum, easy to work with. Im probably going to put some insulation between the old firewall and my new one, mostly so it sits more flat, theres a couple random screws, knobs, odds and ends in the way. Before with my small block it seems like the distributor was pretty close to the firewall. Since im putting this new one in id like to be sure I have enough room, since this will be out a little further. Any suggestions?

One, make sure you use the Big block motor mount BRACKETS. I think if you use the small block brackets the engine will set back farther than if using the big block brackets, not much but if you need room. Also seems you won't be using the heater. An A/C delete would help you there but not with the hole welded. Hope you do a good job with that firewall, I've seen some that come out pretty BAD. And some that are GREAT.

Yeah, well its no show car, and I guess the good thing here is it cant look any worse, its one ugly beast of a firewall now. Its a good project on the side while the motor is getting prepped. Im going to use new BB mounts.

Big block mounts and brackets to cross member.

The bigblock has the same length dimension as a smallblock from the motor mounts back. The bigblock motor mounts only change the heigth of the engine. We are very lucky that chevrolet designed both engines this way making bigblock swaps into smallblock cars a lot easier. I keep a bare bigblock and smallblock block to use for mockups. As your machine shop to borrow a cracked/junk block for mockups just to be sure your clearances are right-better to know now when you're making the mods than to fight with it when installing the new engine, JMO, Bob

Thanks for clearing that up Bob

I was wondering which way they were larger, I assumed right I guess. For once... Will it be difficult to mount it to the transmission with hieght differences?

Well its good to know about the length for the firewall, its coming along ok so far. I did the passenger side where the AC was, somewhat easy because there arent alot of things to go through or around. Cant wait to get to the master cyl, and wiper motor, steering column smile.gif blah.

The height differences shouldn't affect anything other than the driveshaft angle, but I've never heard of anyone having problems.

OK here's a slick tip for those who need more room in the firewall. Go to ToysRus and buy one of those small steel kids wheelbarrows. Remove everything from the tub. Place the tub against your firewall center and mark around the edge of the tub (outside edge upside down against the firewall. Cut a hole in the firewall along the marks you made. Turn the wheelbarrow tub inside out and slide it into the hole and weld it up. makes a great recessed area behind the distributor and the form is perfect.

Hey ChevysRus, have any pics? Are you from the Brentwood Ca. that's near Hollywood, or the one near Oakley?

My dad grew up in Brentwood and went to Brentwood High. I used to go to the 4th of July celebration every year in the city park with relatives that lived in that town.

Steve

That would be Brentwood next to Santa Monica to be exact. :D

Someone was talking about making the surface flat, which ive mostly done with "the insulator" good stuff, used it for padding, sound barrier, and made everything flat. Talking about the Toys R Us idea when it comes to the distributor, that brings up something I was concerned about. My old Dist. sat pretty close to the firewall, now its going to be out a tad further, maybe i'll just get one of those short style ones. The Accel HEI is kind of bulky anyways, which is what I used to have. I think it will be alright....

For the seam across the top of the new firewall, I was thinking about using some kind of filler or wheatherstripping to make it look nicer. When it comes to bolts, I want mine to show, kind of ruggid looking, maybe some little stainless screws, or rivets or something... not sure yet. Gotta go to OSH smile.gif

i stripped out my ac/heat system.firewall looked bad with the crappy welding by the previous owner.
went to lowe's and screwed a piece of aluminum diamond plate where the a/c box used to be.
looks real good.
i just might do the entire firewall this winter.
david

Yeah sounds like your firewall looked like mine smile.gif Nasty. Now that theres no engine I cant decide how low to take the new wall in the center where the engine and block will be, I think Im making it come a little higher, and just avoiding that dip "wheel barrow" area.

For the seam across the top. You could use door guard edging. Or go to Home depot or hardware store and look for the u shaped rubber or vinyl pieces that go around windows or items like that.

Perfect, thanks! That will look really nice

http://img.photobucket.com/albums/v138/Supercharger/fire3.jpg

http://img.photobucket.com/albums/v138/Supercharger/Fire.jpg

Not very exciting right now, I have a couple pieces of cut aluminum, not in the pics. But I cut some insulation and used 3M adhesive. This basically shows the shape that the aluminum is in. Its going to be a 3 piece firewall. What do you think about the shape and size of it?