What spline input/output shaft does the tranny have? A stock t-5 bellhousing will work just fine with it. You'll need a shifter for a 3550, clutch disk and PP (depending on splines), and you don't need to modify a t-5 cross member to fit, it will work just fine. If it were an auto cross member then it would need cutting and rewelding.. My .02
1991 GT with GT-40P heads, Polished typhoon upper and lower, E-cam, 1.6 rr's, Trick flow valve springs, BBK shorties, 70mm TB and EGR,70mm mass air, 190lph pump, BBK regulator (42psi) MSD wires and coil.