[graygator]

Why is the passenger side engine mount shorter than the driver side mount?
I have a 69 Lemans convertible with a 1974 455. The passenger side header is at least an inch lower than the driver side. The engine has a noticeable tilt to the passenger side. The headers are of unknown brand, they came with the car when I bought it. They could be part of the problem, but the engine tilt is noticeable. See photos.

[Mr. G]

IIRC, the passenger side motor mount on the frame side has some adjustment built in by way of the holes in the frame being elongated from the factory. I would check that first followed by the mounts bolted to the engine block as they may be worn or low quality replacements. The headers should not be a factor in how the engine sits on the mounts.

[graygator]

I resolved most of this issue by installing a new passenger side motor mount and by adding a shim under the frame side bracket, also on the passenger side. The engine tilt decreased from 2.5 deg to about 0.5 deg. The passenger side header is now only about 1/4" lower than the driver side. The old motor mount appeared to be slightly bent and slightly shorter (compared to the new one).

[Mr. G]

looks good! I had no idea that shims existed for the frame side mount so that is good to know.