What you have is bad roll couple. Either spring rates front to back are off or roll bars are not matched. Try a 15/16" roll bar in front with no bar in the rear. F41 springs in front and back should get you in the ball park. I have some old F41 front springs if you want them. Sell them cheap.
Both my son and I run manual brakes in dedicated C3 roadracers with VARA and SVRA without any issues. Much easier to modulate braking and no issues related to vacuum dropping under acceleration. I am running a Tilton 5.5" diameter clutch with an automatic flex plate. You will find this takes...