would a gsr rear swaybar fit the subframe reinforcement??

 

gsr bar is only 14mm, nowhere near thick enough to warrant a reinforcement kit.

IIRC the D-bracket bolts were spaced differently on the gsr oem and the bolts through any of the brace kits. you would have to find a new set of d-brackets/bushings that will accept the bolt spacing for your particular kit.
it is still completely unneccessary for that bar though, especially on an eg chassis.