Could buy 2 of the
inexpensive low profile floor jacks from Harbor Freight, place 1 under the fire wall on each side of the FGT, and take a bunch of weight off the tires ... like all of it, if you want, except a few pounds so the car doesn't teeter.
Those are 1.5-ton jacks = 3,000 lbs, so 2 would lift the car entirely off the floor ... except for the teetering issue. Since those are hydraulic they'll eventually leak down, but if your only concern is tire flat spots, maybe a very slow leak down is acceptable (just pump back up occasionally). If not, maybe lift the car a bunch and then put a wood block under the fire wall on each side ... again, prob best to keep all 4 tires touching the floor, at least maybe 25-50 lbs worth.
Just FYI ... With an FGT weight of say 3,500 lbs, and a 43%F / 57%R weight distribution, that'd be 753 lbs on each front tire and 998 lbs on each rear tire ... some figures for thought.