There is not really a "double firewall". The structure is actually a channel (30 in picture below) welded to the engine bay side of lower section of the firewall (39). It also has a couple of reinforcements (31, 32, 34) welded to it. This acts as a torque bar across the rear. That is why you DO NOT remove the actual torque bar or cut it's welds away from the firewall. What you do is only cut the sheet metal between the "ribs" of the channel. The channel is approx. 8" high and 2.5" deep. When you consider that a sub is usually a minimum of 4 inches deep and greater, this space can reduce the depth of your sub box by almost half!
The passenger side is clear in back. You can almost cut a hole as big as the "outline".
Start small, so you can see exactly where the channel is located.
The right side has the gas filler pipe within the wall. Cut carefully, DO NOT use a welding torch!!
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3.4L S/C 87 GT
www.fierosound.com 2002/2003/2004 World of Wheels Winner &
Multiple IASCA Stereo Award Winner
[This message has been edited by fierosound (edited 05-27-2006).]
