High speed stability issues

I just went through that, with a B body, the car hadn’t been on the road since 1994 and all the suspension was new, we put our extra engine from our Dart in it with a mild cam. The car had stability issues at the top end at 117, we put spc uppers and aligned it a couple times and tried it at the track. We finally settled on 5 degrees Caster 1/8 toe and 1/2 degree of camber and changed to a little stiffer front shocks and it didn’t hurt the hook up. We had Calvert 90/10 but they we very soft both ways, so I had a set of cheap competition engineering shocks and put those on, now its perfect, pretty scary before. Maybe time for double adjustables