hi
according to this post:
http://www.gt40s.com/ubbthreads/showflat.php/Cat/0/Number/52087/an/0/page/0#52087
The original suspension travel seems to be 3,5" at front and 3" at rear. Ride height original is 4,5" as i recall but that can vary depending on road conditions
Hope tis helps
ingvar