When I was mocking mine up it looked like there were a few exhaust options that would have worked, but all of them still would have required spacing out the steering box.
I didn't have to modify the firewall at all - I'll try to take a picture of my setup today.
Here's a picture of mine when I was trying to decide what to do with the steering- in this pic the engine is offset 1" to the passenger side:
[img]
http://i48.photobucket.com/albums/f214/tkeahi/CIMG0109.jpg[/img]
Kind of hard to see but the spark plug is about 3mm from the steering box bolt. From this picture you can kind of see how moving the engine up an inch and forward an inch might have helped. It also looks like shorty spark plugs, a spaced out steering box, and an offset engine might have worked but I didn't like that idea. I didn't want the steering wheel at an angle even if I was the only one who ever would have noticed.
I think the idea of moving the steering box along the frame would work if you could figure out the linkage. I cut off my old steering column about 3" above the box so if you want the box to play with it you're welcome to it.
Here's some pictures I found online (not mine):
[img]
http://i48.photobucket.com/albums/f214/tkeahi/IM002583.jpg[/img]
[img]
http://i48.photobucket.com/albums/f214/tkeahi/IM002587.jpg[/img]
