Has anyone out there ever measured how much off center the engine is in the chassis? I did a quick measurement and I'm about 15/16" to 1" off the the right. I took the measurement from the carburetor stud to the leading edge of the fender. There may be slight variations depending on how your fenders are aligned and such. I guess to allow for room for the pedals, steering box, clutch linkage and whatever else is squeezed in there. I talked to buddy of mine with a 69 GTX and he told me most Mopars are around 2" off center.
If I remember correctly, mine is pretty close to 3/8 offset to right. Can't remember if that was how much off center or total difference in readings.
I took another measurement off my 1970 Mustang and get about 3/8" off center. If I had 3"8 in my 57 the headers wouldn't even be remotely close in fitting. I have around 7/16"" clearance to the steering box. and that's with grinding some off the cover.
Thats interesting and something I didn't check on the 57. I know my 66 F250 is offset about 2" and I only realized it when checking for new springs, the passenger side is rated higher..