I had a ‘92 SC400, used the shocks, springs, swaybars, and brakes from the MKIV TT.
Also had some 10.5/9 X 17 rims that helped it all work together.
Looking further, it would be a miracle if the GRC struts would swap to the standard car, as everything downstream is entirely different!
The track width is around 2 1/2” wider on the GR, mostly from the knuckles.
Might be worth finding a set of oem GR struts/shocks someone has laying around after upgrading to coilovers, see how it goes.
As for alignment, I have a large “caliper” that I have used to set toe. It’s a length of 3/4” X 4” oak with some maybe 14” extensions on each end, a plastic nub that engages with the rim on one side, and a large flat washer to measure from to the rim, using 6” caliper/depth gauge.
On the back, it still works but in conjunction with a long straight edge to gauge against the front hubs. Wound up with .010” total in front, and about .020” in the rear, has worked on most cars since.