tti header clearance problem

I have a spool mount car but would like to offer a suggestion.
Do you think that shimming the motor mount 1/4" would give you enough clearance?
(Not sure if putting it on the bottom or top would be best.)

Are the motor mounts new or "good". Old mounts can get soft or manufacturers can have slightly different thicknesses. Can the motor be moved around a bit with sandwich mounts like it can be with spool mounts? There can be production tolerance differences as well as a possible "tweak" somewhere after 45 years.

If I'm visualizing this correctly, a torsion bar adjustment would change the inner tie rod to ground measurement, but not affect the header clearance problem.