X-Frame Stiffening

[LeighP]

The car will move around....unless you stiffen it up. I'd recommend adding side rails, repair the sill inners and tie the side rails to the sills...maybe upper and lower longitudinal tubing, tied together with short tube sections (ladder style) - light and stiff. Solid body mounts, and stiffen the body with a cage structure.

Many years ago, I owned a Canadian Pontiac - 63 Laurentian - basically a 63 Chevy with a Pontiac skin. Previous owner had a 396BBC in the car ,with one head chained to the LH chassis rail to stop breaking engine mounts. He put a noticeable twist into the chassis doing that.....so these cars are very easy to bend up.