Both wheelbase and track will be the same as a 4dr KE30 or KE55. The exact track, will be effected by wheel width and offset, so a few slighly different figures can be found. Also note that on a KE30, you have heaps more room at the back and can go a bit wider if you want.
This is my setup: KE55. Complete rear diff assembly from a RA23 Celica. This is about 5 or 10mm wider, so the perfect side. I cut the spring mounts off and welded leaf spring mounts on. I use a LSD center from a early AE86 twincam. I just measured the rear track on my car and its roughly 1290mm. That is with 14 x 6-1/2" wheels, offset -25.